Which was the first antibiotic to be discovered?

First new antibiotic in 30 years discovered in major breakthrough Science First new antibiotic in 30 years discovered in major breakthrough The discovery of Teixobactin could pave the way for a new generation of antibiotics because of the way it was discovered. Sarah Knapton , Science Editor 7 January 2016 • 5:44pm The first new antibiotic to be discovered in nearly 30 years has been hailed as a ‘paradigm shift’ in the fight against the growing resistance to drugs. Teixobactin has been found to treat many common bacterial infections such as tuberculosis, septicaemia and C. diff, and could be available within five years. But more importantly it could pave the way for a new generation of antibiotics because of the way it was discovered. Scientists have always believed that the soil was teeming with new and potent antibiotics because bacteria have developed novel ways to fight off other microbes. But 99 per cent of microbes will not grow in laboratory conditions leaving researchers frustrated  that they could not get to the life-saving natural drugs. Now a team from Northeastern University in Boston, Massachusetts, have discovered a way of using an electronic chip to grow the microbes in the soil and then isolate their antibiotic chemical compounds. They discovered that one compound, Teixobactin, is highly effective against common bacterial infections Clostridium difficile, Mycobacterium tuberculous and Staphylococcus aureus. Professor Kim Lewis, Director of the Antimicrobial Discovery Centre said: “Apart from the immediate implementation, there is also I think a paradigm shift in our minds because we have been operating on the basis that resistance development is inevitable and that we have to focus on introducing drugs faster than resistance “Teixobactin shows how we can adopt an alternative strategy and develop compounds to which bacteria are not resistant.” The first antibiotic Penicillin, was discovered by Alexander Fleming in 1928 and more than 100 compounds have been found since, but no new class has been found since 1987. The lack of new drugs coupled with over-prescribing has led to bacteria becoming increasingly resistant to modern medicines. Dame Sally Davies, the government’s Chief Medical Officer, said antibiotic resistant was ‘as big a risk of terrorism; and warned that Britain faced returning to a 19th century world where the smallest infection or operation could kill. The World Health Oganisation has also classified antimicrobial resistance as a "serious threat’ to every region of the world which ‘has the potential to affect anyone, of any age, in any country" However the new discovery offers hope that many new antibiotics could be found to fight bacterial infections. Crucially, the scientists believe that bacteria will not become resistant to Teixobactin for at least 30 years because of its multiple methods of attack. Testing on mice has already shown that the antibiotic works well at clearing infections, without side-effects. The team is now concentrating on upscaling production so that it could be tested in humans. “Right now we can deliver a dose that cures mice and a variety of models of infection and we can deliver 10 mg per kg so it correlates well with human usage,” added Professor Lewis. The breakthrough was heralded by scientists who said it could prove a ‘game-changer’ in the struggle against antimicrobial resistance. Prof Laura Piddock, Professor of Microbiology at the University of Birmingham, said: “The screening tool developed by these researchers could be a ‘game changer’ for discovering new antibiotics as it allows compounds to be isolated from soil producing micro-organisms that do not grow under normal laboratory conditions.” Prof Mark Woolhouse, Professor of Infectious Disease Epidemiology, from the University of Edinburgh added: “Any report of a new antibiotic is auspicious, but what most excites me about the paper is the tantalising prospect that this discovery is just the tip of the iceberg. “Most antibiotics are natural products derived from microbes in the soil. The ones we have disc


What Is the Boiling Point of Water? What Is the Boiling Point of Water? What Is the Boiling Point of Water? Boiling Point of Water The boiling point of water is 100 degrees Celsius or 212 degrees Fahrenheit at 1 atmosphere of pressure (sea level).  Jody Dole, Getty Images Updated July 21, 2016. Question: What Temperature Does Water Boil? At what temperature does water boil? What determines the boiling point of water? Here's the answer to this common question. Answer: The boiling point of water is 100°C or 212° F at 1 atmosphere of pressure (sea level). However, the value is not a constant. The boiling point of water depends on the atmospheric pressure, which changes according to elevation. The boiling point of water is 100°C or 212° F at 1 atmosphere of pressure (sea level), but water boils at a lower temperature as you gain altitude (e.g., on a mountain) and boils at a higher temperature if you increase atmospheric pressure (lived below sea level ). The boiling point of water also depends on the purity of the water. Water which contains impurities (such as salted water ) boils at a higher temperature than pure water. This phenomenon is called boiling point elevation , which is one of the colligative properties of matter. Learn More


Effective for: Vitamin C deficiency. Taking vitamin C by mouth or injecting as a shot prevents and treats vitamin C deficiency, including scurvy. Also, taking vitamin C can reverse problems associated with scurvy. Likely Effective for: Iron absorption. Administering vitamin C along with iron can increase how much iron the body absorbs in adults and children. A genetic disorder in newborns called tyrosinemia. Taking vitamin C by mouth or as a shot improves a genetic disorder in newborns in which blood levels of the amino acid tyrosine are too high. Possibly Effective for: Age-related vision loss (age-related macular degeneration; AMD). Taking vitamin C in combination with zinc, vitamin E, and beta-carotene daily seems to help prevent vision loss or slow the worsening of AMD in patients with advanced AMD. There is not enough evidence to know if this combination helps people with less advanced macular disease or if it prevents AMD. Using vitamin C with other antioxidants, but without zinc, does not seem to have any effect on AMD. Decreasing protein in the urine (albuminuria). Taking vitamin C plus vitamin E can reduce protein in the urine in people with diabetes. Hardening of the arteries (atherosclerosis). Taking vitamin C by mouth seems to decrease the risk of artery hardening. Vitamin C also appears to slow the rate at which artery hardening worsens. More research is needed to understand the effects of vitamin C intake from the diet or supplements on this condition once it has developed. Cancer. Consuming vitamin C in the diet might decrease the risk of developing mouth cancers and other cancers. Some research suggests that increasing vitamin C intake through fruits and vegetables reduces the risk of cancer. However, taking vitamin C supplements does not appear to reduce cancer risk. Common cold. There is some controversy about the effectiveness of vitamin C for treating the common cold. However, the majority of evidence shows that taking high doses of vitamin C might shorten the course of the cold by 1 to 1.5 days in some patients. Taking vitamin C is not effective for preventing the common cold. Chronic pain condition (complex regional pain syndrome). Taking vitamin C after a wrist fracture seems to decrease the risk of developing a chronic pain condition called complex regional pain syndrome. Kidney problems related to contrast media used during a diagnostic test called angiography. Taking vitamin C before and after an angiography seems to reduce the risk of developing kidney problems. Redness (erythema) after cosmetic skin procedures. There is some evidence that using a particular vitamin C skin cream can decrease the amount and duration of skin redness following laser resurfacing for scar and wrinkle removal. Lung infections caused by heavy exercise. Using vitamin C before heavy physical exercise, such as a marathon, might prevent upper respiratory infections that sometimes follow heavy exercise. Gallbladder disease. There is some evidence that taking vitamin C might help to prevent gallbladder disease in women. However, vitamin C does not seem to have this effect in men. Ulcers in the stomach caused by bacteria called H. pylori. Taking vitamin C seems to decrease some of the side effects caused by treatment for H. pylori infections. After H. pylori bacteria are killed, vitamin C appears to decrease the development of precancerous lesions in the stomach. However, other research suggests that vitamin C does not improve healing from H. pylori infection. Abnormal breakdown of red blood cells (hemolytic anemia). Treatment with vitamin C can improve hemolytic anemia. High blood pressure. Taking vitamin C along with conventional blood pressure-lowering medications appears to decrease systolic blood pressure (the top number in a blood pressure reading) by a small amount, but does not seem to decrease diastolic pressure (the bottom number). Taking vitamin C supplements alone does not seem to affect blood pressure. Lead poisoning. Consuming vitamin C in the diet seems to lower blood levels of lead. Helping medicines used for


What is the generic term for the mechanical, electrical and electronic components of a computer?

Electro-mechanical Technicians :   Occupational Outlook Handbook: :   U.S. Bureau of Labor Statistics U.S. Bureau of Labor Statistics Summary Electro-mechanical technicians verify dimensions of parts, by using precision measuring instruments, to ensure that specifications are met. Quick Facts:   Electro-mechanical Technicians What Electro-mechanical Technicians Do About this section Electro-mechanical technicians install, repair, upgrade, and test electronic and computer-controlled mechanical systems. Electro-mechanical technicians combine knowledge of mechanical technology with knowledge of electrical and electronic circuits. They operate, test, and maintain unmanned, automated, robotic, or electromechanical equipment. Duties Electro-mechanical technicians typically do the following: Read blueprints, schematics, and diagrams to determine the method and sequence of assembly of a part, machine, or piece of equipment Verify dimensions of parts, using precision measuring instruments, to ensure that specifications are met Operate metalworking machines to make housings, fittings, and fixtures Inspect parts for surface defects Repair and calibrate hydraulic and pneumatic assemblies  Test the performance of electro-mechanical assemblies, using test instruments Install electronic parts and hardware, using soldering equipment and hand tools Operate, test, or maintain robotic equipment Analyze and record test results, and prepare written documentation Electro-mechanical technicians test and operate machines in factories and other worksites. They also analyze and record test results, and prepare written documentation to describe the tests they did and what the test results were. Electro-mechanical technicians install, maintain, and repair automated machinery and equipment in industrial settings. This kind of work requires knowledge and training in the application of photonics, the science of light. The technological aspects of the work have to do with the generating, controlling, and detecting of the light waves so that the automated processes can proceed as designed by the engineers. Electro-mechanical technicians also test, operate, or maintain robotic equipment at worksites. This equipment may include unmanned submarines, aircraft, or similar types of equipment for uses including oil drilling, deep-ocean exploration, or hazardous-waste removal. Work Environment About this section Electro-mechanical technicians test the performance of electro-mechanical assemblies, using test instruments. Electro-mechanical technicians held about 14,700 jobs in 2014. The industries that employed the most electro-mechanical technicians were as follows: Navigational, measuring, electromedical, and control instruments manufacturing 13% Machinery manufacturing 7 Electro-mechanical technicians work closely with electrical and mechanical engineers . They work in many industrial environments, including energy, plastics, computer, and communications equipment manufacturing, and aerospace. They often work both at production sites and in offices. Because their job involves manual work with many machines and types of equipment, electro-mechanical technicians are sometimes exposed to hazards from equipment or toxic materials. However, incidents are rare as long as they follow proper safety procedures. Work Schedules Electro-mechanical technicians often work for larger companies in manufacturing or for engineering firms. Like others at these firms, these technicians tend to work regular shifts. However, sometimes they must work longer hours to make repairs so that manufacturing operations can continue. How to Become an Electro-mechanical Technician About this section Electro-mechanical technicians typically need either an associate’s degree or a postsecondary certificate. Electro-mechanical technicians typically need either an associate’s degree or a postsecondary certificate. Education Associate’s degree programs and postsecondary certificates for electro-mechanical technicians are offered at vocational–technical schools and community colleges. Vocatio


Whose research on X-ray diffraction of ?DNA crystals helped Crick and Watson during the race to discover the structure of DNA?

A Science Odyssey: People and Discoveries: Watson and Crick describe structure of DNA Watson and Crick describe structure of DNA 1953 Photo: Model of DNA molecule In the late nineteenth century, a German biochemist found the nucleic acids, long-chain polymers of nucleotides, were made up of sugar, phosphoric acid, and several nitrogen-containing bases. Later it was found that the sugar in nucleic acid can be ribose or deoxyribose, giving two forms: RNA and DNA. In 1943, American Oswald Avery proved that DNA carries genetic information. He even suggested DNA might actually be the gene. Most people at the time thought the gene would be protein, not nucleic acid, but by the late 1940s, DNA was largely accepted as the genetic molecule. Scientists still needed to figure out this molecule's structure to be sure, and to understand how it worked. In 1948, Linus Pauling discovered that many proteins take the shape of an alpha helix, spiraled like a spring coil. In 1950, biochemist Erwin Chargaff found that the arrangement of nitrogen bases in DNA varied widely, but the amount of certain bases always occurred in a one-to-one ratio. These discoveries were an important foundation for the later description of DNA. In the early 1950s, the race to discover DNA was on. At Cambridge University, graduate student Francis Crick and research fellow James Watson (b. 1928) had become interested, impressed especially by Pauling's work. Meanwhile at King's College in London, Maurice Wilkins (b. 1916) and Rosalind Franklin were also studying DNA. The Cambridge team's approach was to make physical models to narrow down the possibilities and eventually create an accurate picture of the molecule. The King's team took an experimental approach, looking particularly at x-ray diffraction images of DNA. In 1951, Watson attended a lecture by Franklin on her work to date. She had found that DNA can exist in two forms, depending on the relative humidity in the surrounding air. This had helped her deduce that the phosphate part of the molecule was on the outside. Watson returned to Cambridge with a rather muddy recollection of the facts Franklin had presented, though clearly critical of her lecture style and personal appearance. Based on this information, Watson and Crick made a failed model. It caused the head of their unit to tell them to stop DNA research. But the subject just kept coming up. Franklin, working mostly alone, found that her x-ray diffractions showed that the "wet" form of DNA (in the higher humidity) had all the characteristics of a helix. She suspected that all DNA was helical but did not want to announce this finding until she had sufficient evidence on the other form as well. Wilkins was frustrated. In January, 1953, he showed Franklin's results to Watson, apparently without her knowledge or consent. Crick later admitted, "I'm afraid we always used to adopt -- let's say, a patronizing attitude towards her." Watson and Crick took a crucial conceptual step, suggesting the molecule was made of two chains of nucleotides, each in a helix as Franklin had found, but one going up and the other going down. Crick had just learned of Chargaff's findings about base pairs in the summer of 1952. He added that to the model, so that matching base pairs interlocked in the middle of the double helix to keep the distance between the chains constant. Watson and Crick showed that each strand of the DNA molecule was a template for the other. During cell division the two strands separate and on each strand a new "other half" is built, just like the one before. This way DNA can reproduce itself without changing its structure -- except for occasional errors, or mutations. The structure so perfectly fit the experimental data that it was almost immediately accepted. DNA's discovery has been called the most important biological work of the last 100 years, and the field it opened may be the scientific frontier for the next 100. By 1962, when Watson, Crick, and Wilkins won the Nobel Prize for physiology/medicine, Franklin had died. The Nobel Prize only goes to living


Heisenberg is most associated with which branch of physics?

The Uncertainty Principle (Stanford Encyclopedia of Philosophy) Stanford Encyclopedia of Philosophy The Uncertainty Principle First published Mon Oct 8, 2001; substantive revision Tue Jul 12, 2016 Quantum mechanics is generally regarded as the physical theory that is our best candidate for a fundamental and universal description of the physical world. The conceptual framework employed by this theory differs drastically from that of classical physics. Indeed, the transition from classical to quantum physics marks a genuine revolution in our understanding of the physical world. One striking aspect of the difference between classical and quantum physics is that whereas classical mechanics presupposes that exact simultaneous values can be assigned to all physical quantities, quantum mechanics denies this possibility, the prime example being the position and momentum of a particle. According to quantum mechanics, the more precisely the position (momentum) of a particle is given, the less precisely can one say what its momentum (position) is. This is (a simplistic and preliminary formulation of) the quantum mechanical uncertainty principle for position and momentum. The uncertainty principle played an important role in many discussions on the philosophical implications of quantum mechanics, in particular in discussions on the consistency of the so-called Copenhagen interpretation, the interpretation endorsed by the founding fathers Heisenberg and Bohr. This should not suggest that the uncertainty principle is the only aspect of the conceptual difference between classical and quantum physics: the implications of quantum mechanics for notions as (non)-locality, entanglement and identity play no less havoc with classical intuitions. Related Entries 1. Introduction The uncertainty principle is certainly one of the most famous aspects of quantum mechanics. It has often been regarded as the most distinctive feature in which quantum mechanics differs from classical theories of the physical world. Roughly speaking, the uncertainty principle (for position and momentum) states that one cannot assign exact simultaneous values to the position and momentum of a physical system. Rather, these quantities can only be determined with some characteristic “uncertainties” that cannot become arbitrarily small simultaneously. But what is the exact meaning of this principle, and indeed, is it really a principle of quantum mechanics? (In his original work, Heisenberg only speaks of uncertainty relations.) And, in particular, what does it mean to say that a quantity is determined only up to some uncertainty? These are the main questions we will explore in the following, focusing on the views of Heisenberg and Bohr. The notion of “uncertainty” occurs in several different meanings in the physical literature. It may refer to a lack of knowledge of a quantity by an observer, or to the experimental inaccuracy with which a quantity is measured, or to some ambiguity in the definition of a quantity, or to a statistical spread in an ensemble of similarly prepared systems. Also, several different names are used for such uncertainties: inaccuracy, spread, imprecision, indefiniteness, indeterminateness, indeterminacy, latitude, etc. As we shall see, even Heisenberg and Bohr did not decide on a single terminology for quantum mechanical uncertainties. Forestalling a discussion about which name is the most appropriate one in quantum mechanics, we use the name “uncertainty principle” simply because it is the most common one in the literature. 2. Heisenberg 2.1 Heisenberg’s road to the uncertainty relations Heisenberg introduced his famous relations in an article of 1927, entitled Ueber den anschaulichen Inhalt der quantentheoretischen Kinematik und Mechanik. A (partial) translation of this title is: “On the anschaulich content of quantum theoretical kinematics and mechanics”. Here, the term anschaulich is particularly notable. Apparently, it is one of those German words that defy an unambiguous translation into other languages. Heisenberg’s title is translated as “On


What did Heike Kamerlingh-Onnes discover?

Heike Kamerlingh Onnes - Biography, Facts and Pictures Blog Heike Kamerlingh Onnes A Dutch physicist, Heike Kamerlingh Onnes was the pioneer of refrigeration techniques and the one who studied how materials behave when they are cooled to almost absolute zero temperature. He was also the first person to liquefy helium, and because of his experiments concerning cryogenics as well as extremely low temperature, he was able to discover superconductivity. He also noted how the rate of electrical resistance can vanish at much lower temperatures for certain materials. Early Life and Educational Background Heike was born on the 21st of September in 1853 and was a native of Groningen in the Netherlands. Harm Kamerlingh Onnes, his father, owned brickworks near his birth town. Anna Gerdina Coers, his mother, was an architect’s daughter from Arnhem. His exposure to such fields may have piqued his interest when it came to making his very own discoveries later on in his life. Advertisements He was educated at the local Hoogere Burgerschool which was a native secondary school that did not have classical languages. After spending the required time for secondary school, he was able to get supplementary education on Latin and Greek from Leyden J.M. van Bemmelen who later became his Chemistry professor. After his supplementary education on classical languages, he went to the University of Groningen where he worked on obtaining the “candidaats” degree. A year after studying at the University of Groningen, he proceeded to Heidelberg where he furthered his education from 1871 up to 1873. After his time there, he made his way back to Groningen and this was where he was able to pass his “doctoraal” exams in 1879. A year later, he was able to obtain his doctoral degree and he had his thesis called the New Proofs of the Rotation of the Earth which was originally entitled Nieuwebewijzenvoor de aswenteling der aarde. In this doctoral work, he proved through theoretical and experimental means how the Foucault’s pendulum experiment must be seen as a kind of special, large group phenomena which, when simplified, can prove how the earth moved in a rotational manner. In 1881, Heike published Algemeenetheorie der vloeistoffen or the general theory of liquids which discussed the kinetic theory of matter in liquid state. Here, he approached his work using the Van der Waal law while also having a mechanistic back up to it. His work on the general theory of liquids sparked his lifelong dedication to investigate more on how matter behaves when subjected to very low temperatures. He had his inaugural address known as the importance of quantitative research in physics where he said his now famous motto: “Knowledge through measurement” or “Door metentotweten.” Little did he realize this belief had materialized because of his appreciation of how important measurements were concerning his lifelong engagement in scientific experiments. Scientific Career and Endeavors It was in 1871 when his outstanding skills in solving scientific problems were made obvious at the young age of 18. That year he received a gold medal for winning a competition which was held by the University of Utrecht’s Natural Sciences Faculty. The following year he received a silver medal from the University of Groningen. While he was still working on his doctoral degree, he was an assistant at the Polytechnicum which was in Delft. He also became a lecturer in the area for a year from 1881. Because of this, he was appointed as the Professor of Experimental Physics and Meteorology after P.L. Rijke held the same post. After he got appointed as the chair of Physics, he made changes to the Physical Laboratory which is now named after him and is called the Kamerlingh Onnes Laboratory. He made the necessary changes so that the place would be fitted to be the most suitable place for his own program. More particularly, the changes he made were aimed towards having his own cryogenic laboratory that would help him verify the idea Van der Waal had about corresponding states of matter in relation to the temper


What science is the study of missiles in motion?

ballistics Encyclopedia  >  Science and Technology  >  Physics  >  Physics ballistics ballistics (bəlĭsˈtĭks) [ key ], science of projectiles. Interior ballistics deals with the propulsion and the motion of a projectile within a gun or firing device. Its problems include the ignition and burning of the propellant powder, the pressure produced by the expanding gases, the movement of the projectile through the bore, and the designing of the barrel to resist resulting stresses and strains. Exterior ballistics is concerned with the motion of a projectile while in flight and includes the study not only of the flight path of bullets but also of bombs, rockets, and missiles. All projectiles traveling through the air are affected by wind, air resistance, and the force of gravity. These forces induce a curved path known as a trajectory. The trajectory varies with the weight and shape of the projectile, with its initial velocity, and with the angle at which it is fired. The general shape of a trajectory is that of a parabola. The total distance traveled by a projectile is known as its range. A ballistic missile in the first stage of its flight is powered and guided by rocket engines. After the engines burn out, the warhead travels in a fixed arc as does an artillery shell. In criminology the term ballistics is applied to the identification of the weapon from which a bullet was fired. Microscopic imperfections in a gun barrel make characteristic scratches and grooves on bullets fired through it, but use causes the marks a particular gun makes to change over time. See E. D. Lowry, Interior Ballistics (1968); R. C. Labile, Ballistic Materials and Penetration Mechanics (1980); A. J. Pejsa, Modern Practical Ballistics (1989); M. Denny, Their Arrows Will Darken the Sun: The Evolution and Science of Ballistics (2011). The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved. See more Encyclopedia articles on: Physics


What kind of elements are found in a pure state in nature?

Elements and Compounds About Watch and Favorite Watch Watching this resources will notify you when proposed changes or new versions are created so you can keep track of improvements that have been made. Favorite Favoriting this resource allows you to save it in the “My Resources” tab of your account. There, you can easily access this resource later when you’re ready to customize it or assign it to your students. Elements and Compounds An element is a material that consists of a single type of atom, while a compound consists of two or more types of atoms. Learning Objective Differentiate between elements and compounds and explore separation techniques Key Points Elements are the simplest complete chemical substances . Each element corresponds to a single entry on the periodic table. An element is a material that consists of a single type of atom . Each atom type contains the same number of protons . Chemical bonds link elements together to form more complex molecules called compounds . A compound consists of two or more types of elements held together by covalent or ionic bonds . Elements cannot be divided into smaller units without large amounts of energy . Compounds, on the other hand, can have their bonds broken with practical amounts of energy, such as the heat from a fire. Matter can be broken down into two categories: pure substances and mixtures . Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated back into their original components. Terms Full Text Elements A chemical element is a pure substance that consists of one type of atom. Each atom has an atomic number , which represents the number of protons that are in the nucleus of a single atom of that element. The periodic table of elements is ordered by ascending atomic number. The chemical elements are divided into the metals , the metalloids , and the non-metals. Metals, typically found on the left side of the periodic table, are: often conductive to electricity sometimes magnetic. Aluminum , iron, copper , gold, mercury and lead are metals. In contrast, non-metals, found on the right side of the periodic table (to the right of the staircase), are: typically not conductive not magnetic. Examples of elemental non-metals include carbon and oxygen . Metalloids have some characteristics of metals and some characteristics of non-metals. Silicon and arsenic are metalloids. As of November, 2011, 118 elements have been identified (the most recently identified was ununseptium, in 2010). Of these 118 known elements, only the first 98 are known to occur naturally on Earth. The elements that do not occur naturally on Earth are the synthetic products of man-made nuclear reactions. 80 of the 98 naturally-occurring elements are stable; the rest are radioactive, which means they decay into lighter elements over timescales ranging from fractions of a second to billions of years. The periodic table shows 118 elements, including metals (blue), nonmetals (red), and metalloids (green). Hydrogen and helium are by far the most abundant elements in the universe. However, iron is the most abundant element (by mass) in the composition of the Earth, and oxygen is the most common element in the layer that is the Earth's crust. Although all known chemical matter is composed of these elements, chemical matter itself constitutes only about 15% of the matter in the universe. The remainder is dark matter, a mysterious substance that is not composed of chemical elements. Dark matter lacks protons, neutrons , or electrons . Compounds Pure samples of isolated elements are uncommon in nature. While the 98 naturally occurring elements have all been identified in mineral samples from the Earth's crust, only a small minority of them can be found as recognizable, relatively pure minerals. Among the more common of such "native elements" are copper, silver , gold, and sulfur. Carbon is also commonly found in the form of coal, graphite, and diamonds . The noble gases (e.g., neon) and noble metals (e.g., mercury) can also be


"What are classified by their measurement in degrees as ""right"", ""reflex"", ""obtuse"", or ""acute""?"

Angles - Acute, Obtuse, Straight and Right Angles An angle measures the amount of turn Names of Angles As the Angle Increases, the Name Changes: Type of Angle an angle that is greater than 90° but less          than 180° an angle that is greater than 180° Try It Yourself: This diagram might make it easier to remember: Also: Acute, Obtuse and Reflex are in alphabetical order.   Also: the letter "A" has an acute angle. Be Careful What You Measure This is an Obtuse Angle And this is a Reflex Angle   But the lines are the same ... so when naming the angles make sure that you know which angle is being        asked for! Positive and Negative Angles When measuring from a line: a positive angle goes counterclockwise (opposite direction that clocks go) a negative angle goes clockwise Example: −67° The corner point of an angle is called the vertex And the two straight sides are called arms The angle is the amount of turn between each arm.   How to Label Angles There are two main ways to label angles: 1. give the angle a name, usually a lower-case letter like a or b, or sometimes a Greek letter like α (alpha) or θ (theta) 2. or by the three letters on the shape that define the angle, with the middle letter being where the angle actually is (its vertex). Example angle "a" is "BAC", and angle "θ" is "BCD"


What is the name given to the longest side of a right-angled triangle?

Naming the Sides of a Right-Angled Triangle Year 10 Interactive Maths - Second Edition Naming the Sides of a Right-Angled Triangle The side opposite the right angle is called the hypotenuse.  It is the largest side of a right-angled triangle. If you stand at A in the triangle ABC, the side BC is opposite to you and the side AB is next to you.  We          therefore say that BC is the opposite side to angle A and AB is the adjacent side to angle A. Notation If you have trouble remembering the definitions, just remember SOH           CAH TOA. Using a Graphics Calculator If you have a TI-83 graphics calculator, select Degree from the MODE menu and set Float to 4 to obtain the answers correct to 4 decimal places.  Press QUIT to return to the Home Screen and clear the          screen if necessary. If you are using another calculator, consult its instruction booklet or          ask your teacher how you can set its Mode to 'Degree mode' and the decimal          places display to 4 places. Example 1 Evaluate the following to 4 decimal places: Solution: This is abbreviated as follows: Example 2 Note: Key Terms


Which Swedish scientist had a temperature scale named after him?

Anders Celsius - Centigrade Scale and Thermometer By Mary Bellis In 1742, Swedish astronomer, Anders Celsius invented the Celsius temperature scale, which was named after the inventor. Celsius Temperature Scale The Celsius temperature scale is also referred to as the centigrade scale. Centigrade means "consisting of or divided into 100 degrees". The Celsius scale, invented by Swedish Astronomer Anders Celsius (1701-1744), has 100 degrees between the freezing point (0 C) and boiling point (100 C) of pure water at sea level air pressure. The term "Celsius" was adopted in 1948 by an international conference on weights and measures. Anders Celsius Anders Celsius was born in Uppsala, Sweden in 1701, where he succeeded his father as professor of astronomy in 1730. It was there that he built Sweden's first observatory in 1741, the Uppsala Observatory, where he was appointed director. He devised the centigrade scale or "Celsius scale" of temperature in 1742. He was also noted for his promotion of the Gregorian calendar, and his observations of the aurora borealis. continue reading below our video 5 Best Places to Retire In 1733, his collection of 316 observations of the aurora borealis was published and in 1737 he took part in the French expedition sent to measure one degree of meridian in the polar regions. In 1741, he directed the building of Sweden's first observatory. One of the major questions of that time was the shape of the Earth. Isaac Newton had proposed that the Earth was not completely spherical, but rather flattened at the poles. Cartographic measuring in France suggested that it was the other way around - the Earth was elongated at the poles. In 1735, one expedition sailed to Ecuador in South America, and another expedition traveled to Northern Sweden. Celsius was the only professional astronomer on that expedition. Their measurements seemed to indicate that the Earth actually was flattened at the poles. Anders Celsius was not only an inventor and astronomer, but also a physicist. He and an assistant discovered that the aurora borealis had an influence on compass needles. However, the thing that made him famous is his temperature scale, which he based on the boiling and melting points of water. This scale, an inverted form of Celsius' original design, was adopted as the standard and is used in almost all scientific work. Anders Celsius died in 1744, at the age of 42. He had started many other research projects, but finished few of them. Among his papers was a draft of a science fiction novel, situated partly on the star Sirius.


How many colors are there in the spectrum when white light is separated?

Red .622-.780 Like energy passing through the ocean, light energy travels in waves, too. Some light travels in short, "choppy" waves. Other light travels in long, lazy waves. Blue light waves are shorter than red light waves. All light travels in a straight line unless something gets in the way to-- reflect it (like a mirror) bend it (like a prism) or scatter it (like molecules of the gases in the atmosphere) Sunlight reaches Earth's atmosphere  and is scattered in all directions by all the gases and particles in the air.  Blue light is scattered in all directions by the tiny molecules of air in  Earth's atmosphere. Blue is scattered more than other colors because it  travels as shorter, smaller waves. This is why we see a blue sky most of the  time. Closer to the horizon, the sky fades to a lighter blue or white. The sunlight reaching us from low in the sky has passed through even more air than the sunlight reaching us from overhead. As the sunlight has passed through all this air, the air molecules have scattered and rescattered the blue light many times in many directions. Also, the surface of Earth has reflected and scattered the light. All this scattering mixes the colors together again so we see more white and less blue. Why do we see rainbows in the sky?  A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere. They take the form of a multi-colored arc, with red on the outer part of the arch and violet on the inner section of the arch. A rainbow spans a continuous spectrum of colors. Traditionally, however, the sequence is quantised. The most commonly cited and remembered sequence, in English, is Newton's sevenfold in order from longest to shortest wavelength: red, orange, yellow, green, blue, indigo and violet.  "Roy G. Biv" and "Richard Of York Gave Battle In Vain" are popular mnemonics. Rainbows can be caused by other forms of water than rain, including mist, spray, and dew. Sunlight contains many different colors. Normally, we see all the colors mixed together as white light. We see a rainbow when sunlight separates into bands of different colors. These bands of red, orange, yellow, green, blue, indigo, and violet light are also known as the visible spectrum.  A rainbow is created when sunlight passes through raindrops. Light travels through different substances at different speeds. When light travels through water, it slows down. The reduced speed causes light to bend or refract.  To understand how a rainbow is made, it is helpful to understand how a prism works. A prism is a triangular shaped piece of glass. The path of a light beam changes as it goes through a prism. Glass slows the speed of light. When light travels through a prism, it is refracted once while going in and again as it passes through. The refraction separates white light into its many colors.  A water drop acts like a prism. Light refracts as it enters and leaves a drop of water. The refracting light is separated into the colors of the spectrum. When the sky is filled with drops of water, a rainbow is created. Light that enters the drops is refracted. Refraction makes each color visible in its own band. Each color of the spectrum has a slightly different wavelength. The different wavelengths bend in slightly different ways. Long wavelengths bend the least, while short wavelengths refract the most. Red light has the longest wavelength and violet light has the shortest. The other colors have wavelengths that fall between. Because color refraction is consistent, the colors of the rainbow or any other spectrum look the same and appear in the same order. We use the memory device ROYGBV (Roy G. Biv) to signify the order of colors.  The combination of all the separated colors creates the beautiful arching rainbow. Since light needs to pass through the raindrops, rainbows are always seen in the part of the sky opposite the Sun. We see the colors of a typical rainbow as lig


PHYSICS FOLIO |authorSTREAM PHYSICS FOLIO   Does not support media & animations   Automatically changes to Flash or non-Flash embed   The presentation is successfully added In Your Favorites . Views:   This Presentation is Public   Favorites:  0 ENTRY NO. 1: Physics A Natural Philosophy: ENTRY NO. 1: Physics A Natural Philosophy ENTRY NO. 1:  Physics A Natural Philosophy Physics A Natural Philosophy: Physics A Natural Philosophy Physics as natural philosophy. Physics is present in our environment at all times. The gravitational theory is the perfect explanation for this natural philosophy. Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. In everyday life, gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped. ENTRY NO.2 PHYSICS REALLY WORKS: ENTRY NO.2 PHYSICS REALLY WORKS Physics Really Works: Physics Really Works Physics really works. A branch of physics, which is electromagnetism, can be seen in modern inventions. Electromagnetism is the force that causes the interaction between electrically charged particles; the areas in which this happens are called electromagnetic fields. This is the set-up in a MICROPHONE. sound waves enter the microphone, which cause the microphone to vibrate back and forth. This subsequently causes the wire loops to oscillate, and the magnetic field through the plane of the loops subsequently changes, inducing a current in the wires. In this way sound or wave energy is converted into electrical energy. ENTRY NO. 3: TESTING TIME : ENTRY NO. 3: TESTING TIME PHYSICS TRIVIAS:: PHYSICS TRIVIAS: Q:  What did scientists build in a squash court under a football stadium at the University of Chicago in 1942? A:  A nuclear reactor. Slide 8: Q: Which Swedish scientist had a temperature scale named after him? A: Anders Celsius. Slide 9: Q :What is the term used to denote the tendency of an object to remain in a state of rest until acted upon by an external force? A: Inertia. Slide 10: Q: The discovery of which law provoked the surprised cry 'Eureka!'? A: Archimedes Principle. Slide 11: Q: Which electronic device magnifies the strength of a signal? A: Amplifier. Slide 12: Q :What is an unchanging position in which forces cancel each other out? A: Equilibrium. Slide 13: Q: What was the name of the unit of heat now replaced by the joule? A: Calorie. Slide 14: Q: What is described as an ionized gas with approximately equal numbers of positive and negative charges? A: Plasma. ENTRY NO. 4: EUREKA EXPERIENCE: ENTRY NO. 4: EUREKA EXPERIENCE My Eureka Experience..: My Eureka Experience.. I have learned a lot of things in my fourth year life now. One of those lessons I’ve learned was the accuracy of measurement. Once we where able to measure using the Vernier caliper. First it was so hard because I’m not familiar with it but Aldrin teach me and now I know how to read its measurement. Eureka! Eureka! ENTRY NO. 5: MEDIA HYPE: ENTRY NO. 5: MEDIA HYPE Media Hype: Media Hype The advertisement of the shampoos and conditioners are one of the best example of media hype. The commercial says that you will have a smoother and healthier hair just like when you go to the parlor. These models and endorsers have some hair treatment before the shoot and some are made by the camera tricks for the commercial so that it will look more beautiful and real. Slide 21: Commercials told us that their products can make our clothes whiter from having dirt after we washed them. They illustrate their product and another product and compared it from one another. The t-shirt that been soaked in their product was much whiter than the other but it looks like it’s a new one and not the original one. Old Quill to Ordinary pen and now. Pen with USB.. At the early age they used the old quill just like Jose Rizal and now there's a lot of hi-tech pens. Pens with camera, with USB or sometimes made from gold.: Old Quill to Ordinary pen and now. Pen with USB.. At the early age they used the old


What is the study and use of frequencies above 20 khz?

There's life above 20 kilohertz! A survey of musical instrument spectra to 102.4 kHz   Author's Notes, May 4, 2000 At the request of people involved in standards-setting for audio, who wanted this information made available as soon as possible, I published this original paper here, rather than in a professional journal. Because I use figures 1(a,b,c) not only as data but to explain my reasoning, I include them in the paper itself. To save download time, other figures are given as links. After you look at one of these figures, your browser's "Back" button may return you to exactly where you were in the paper. If it doesn't, please note what section of the paper you are in before you link to the figure, then return by using the section links supplied with each figure. The footnotes have links to return you to where they were cited. All of the figures are 900 pixels wide. Viewing will be easiest on a monitor screen of 1024 x 768 or higher resolution, and with 256 or more colors.   III. More trumpet, horn, violin, and oboe In the same way as just described for Figure 1, Figures 2 through 9 give information about other instruments whose sound has harmonics.       Skipping Figure 1(c) for the moment, in Figure 2 we see another sample of trumpet with Harmon mute, 20 dB lower in level than the sample in Figure 1, yet with harmonics extending higher, and with a higher percentage of its total energy in the harmonics. (See Table I.) Figure 3 shows trumpet with straight mute. Here the harmonics extend higher yet, to above 85 kHz.       Figures 4 , 5 , and 6 give three examples of French horn, played respectively "bell up," with mute, and in normal fashion. One hundred or more harmonics are visible in each!        Figure 7 shows a violin "double-stop", that is, two notes played simultaneously. Since each note produces its own harmonic series, Figure 7(b) uses markers of two different shapes to show the two harmonic series.        Figure 8 shows a single violin note played sul ponticello, that is, with the bow very close to the bridge. This gives a distinctive squeaky-scratchy sound which composers sometimes specify, as for example Beethoven in the C-sharp Minor string quarter, Opus 131. Even in this mezzo-piano (medium-soft) note, harmonics are still visible past 40 kHz. (Due to absence of mind, I took no sample of normal violin sound playing a single note normally.)        Figure 9 shows an oboe note. It is striking how the harmonics suddenly drop in level after the 40th at 43 kHz.       Not shown are any clarinet or vibraphone samples, because, as mentioned above, I could find no harmonic activity above 20 kHz anywhere in several samples of each, despite the closest "prospecting" with spectrum analyzer. These were the only instruments of the group that did not show such activity.         Figures 18(a) and (b) show the performance of the B&K preamp to signals (c) and (d) respectively. The preamp is clearly free of harmonics at both high and low levels. The small bump at 85 kHz in the low-level test is breakthrough from the switching power supply. [3] I don't know the source of the even smaller bump at 50 kHz. Both are so small that they may be ignored, however.       The behavior of the Aco 4012 preamp was indistinguishable from the B&K 2639 at the higher level, and superior at the lower.       Note that these tests of the preamps are also tests of the H-P 3567A FFT analyzer. From the clean results, one may conclude that neither preamps nor analyzer are creating a false appearance in any of the spectra in this paper.   V. Room acoustics and rattles I assume that the room acoustics are linear, and thus cannot create spurious frequencies in the spectrum. On the other hand, the room does contain objects which could conceivably rattle at ultrasonic frequencies, including loudspeakers, vacuum tubes, fluorescent light fixtures, metal chassis, and so on. What is more, the time samples analyzed for instruments with harmonics were generally long enough (31.25 milliseconds) for the microphone to pick up not only the direct sound of the instru


What is an unchanging position in which forces cancel each other out?

Equilibria - definition of equilibria by The Free Dictionary Equilibria - definition of equilibria by The Free Dictionary http://www.thefreedictionary.com/equilibria Related to equilibria: Punctuated equilibria e·qui·lib·ri·um  (ē′kwə-lĭb′rē-əm, ĕk′wə-) n. pl. e·qui·lib·ri·ums or e·qui·lib·ri·a (-rē-ə) 1. A condition in which all acting influences are canceled by others, resulting in a stable, balanced, or unchanging system. 2. Mental or emotional balance. 3. Physics The state of a body or physical system at rest or in unaccelerated motion in which the resultant of all forces acting on it is zero and the sum of all torques about any axis is zero. 4. Chemistry a. The state of a chemical reaction in which its forward and reverse reactions occur at equal rates so that the concentration of the reactants and products does not change with time. b. The state of a system in which more than one phase exists and exchange between phases occurs at equal rates so that there is no net change in the composition of the system. [Latin aequilībrium : aequi-, equi- + lībra, balance.] equilibrium n, pl -riums or -ria (-rɪə) 1. a stable condition in which forces cancel one another 2. a state or feeling of mental balance; composure 3. (General Physics) any unchanging condition or state of a body, system, etc, resulting from the balance or cancelling out of the influences or processes to which it is subjected. See thermodynamic equilibrium 4. (General Physics) physics a state of rest or uniform motion in which there is no resultant force on a body 5. (Chemistry) chem the condition existing when a chemical reaction and its reverse reaction take place at equal rates 6. (General Physics) physics the condition of a system that has its total energy distributed among its component parts in the statistically most probable manner 7. (Physiology) physiol a state of bodily balance, maintained primarily by special receptors in the inner ear 8. (Economics) the economic condition in which there is neither excess demand nor excess supply in a market [C17: from Latin aequilībrium, from aequi- equi- + lībra pound, balance] e•qui•lib•ri•um (ˌi kwəˈlɪb ri əm, ˌɛk wə-) n., pl. -ri•ums, -ri•a (-ri ə) 1. a state of rest or balance due to the equal action of opposing forces. 2. equal balance between any powers, influences, etc.; equality of effect. 3. mental or emotional balance; equanimity. 4. a state or sense of steadiness and proper orientation of the body. 5. the condition existing when a chemical reaction and its reverse reaction proceed at equal rates. [1600–10; < Latin aequilībrium=aequi- equi - + lībr(a) balance] e•quil′i•bra•to`ry (ɪˈkwɪl ə brəˌtɔr i, -ˌtoʊr i) adj. e·qui·lib·ri·um (ē′kwə-lĭb′rē-əm) 1. Physics The state of a body or physical system that is at rest or in constant and unchanging motion. The sum of all forces acting on a body that is in equilibrium is zero (because opposing forces balance each other). A system that is in equilibrium shows no tendency to alter over time. 2. Chemistry The state of a reversible chemical reaction in which its forward and reverse reactions occur at equal rates so that the concentration of the reactants and products remains the same. equilibrium The state of a reversible chemical reaction at which the forward and backward reactions take place at the same rate ThesaurusAntonymsRelated WordsSynonymsLegend:


Which physicist's law states that equal volumes of all gases, measured at the same temperature and pressure, contain the same number of molecules?

General Chemistry/Gases - Wikibooks, open books for an open world General Chemistry/Gases 3.2 Pressure and Collisions Characteristics of Gases[ edit ] Gases have a number of special characteristics that differentiate them from other states of matter. Here is a list of characteristics of gases: Characteristics of Gases Gases have neither definite shape nor definite volume. They expand to the size of their container. Gases are fluid, and flow easily. Gases have low density, unless compressed. Being made of tiny particles in a large, open space, gases are very compressible. Gases diffuse (mix and spread out) and effuse (travel through small holes). Standard Temperature and Pressure[ edit ] Wikipedia has related information at Standard conditions for temperature and pressure Standard Temperature and Pressure, or STP, is 0 °C and 1 atmosphere of pressure. Expressed in other units, STP is 273 K and 760 torr. The Kelvin and torr are useful units of temperature and pressure respectively that we will discuss later in the following sections. Avogadro's Law[ edit ] Amedeo Avogadro, the Italian chemist. Avogadro's Law is named after him and his discoveries about the behavior of gases Wikipedia has related information at Avogadro's Law Avogadro's Law states that equal volumes of gases at the same temperature and pressure contain the same number of molecules. So both one mole of Xenon at STP (131.3 grams) and one mole of helium at STP (4.00 grams) take up 22.4 liters. Even 1 mole of air, which is a mixture of several gases, takes up 22.4 liters of volume. 22.4 L is the standard molar volume of a gas. [Avogadro's Law] s t {\displaystyle {\frac {p_{1}\cdot V_{1}}{T_{1}\cdot n_{1}}}={\frac {p_{2}\cdot V_{2}}{T_{2}\cdot n_{2}}}=const} where: p is the pressure of the gas T is the temperature of the gas has the same value for all gases, independent of the size or mass of the gas molecules. Pressure[ edit ] Gases exert pressure on their containers and all other objects. Pressure is measured as force per unit area. A barometer is a device that measures pressure. There are a number of different units to measure pressure: torr, equal to millimeters of mercury (mm Hg): if a glass cylinder with no gas in it is placed in a dish of liquid mercury, the mercury will rise in the cylinder to a certain number of millimeters. atmosphere (atm), the pressure of air at sea level. pascal (Pa), equal to one newton (N) per square meter. A newton is the force necessary to accelerate one kilogram by one meter per second squared. You should know that 1 atm = 760 torr = 101.3 kPa. Wikipedia has related information at Ideal gas Gases are complicated things composed a large numbers of tiny particles zipping around at high speeds. There are a number of complex forces governing the interactions between molecules in the gas, which in turn affect the qualities of the gas as a whole. To get around these various complexities and to simplify our study, we will talk about ideal gases. An ideal gas is a simplified model of a gas that follows several strict rules and satisfies several limiting assumptions. Ideal gases can be perfectly modeled and predicted with a handful of equations. Ideal gases follow, among others, these important rules: Rules of Ideal Gases The molecules that make up a gas are point masses, meaning they have no volume. Gas particles are spread out with very great distance between each molecule. Thus, intermolecular forces are essentially zero, meaning they neither attract nor repel each other. If collisions do occur between gas particles, these collisions are elastic, meaning there is no loss of kinetic (motion) energy. Gas molecules are in continuous random motion. Temperature is directly proportionate to kinetic energy. Note: Ideal gases never truly exist (because the nature of gases is so complicated), but gases are often close enough to an ideal gas that the equations still hold fairly accurate. Ideal Gas Law[ edit ] Ideal gases can be completely described using the ideal gas law: [Ideal Gas Law] Real Gases[ edit ] All real gases (or non-ideal gases)


What is the ability of fluids to offer resistance to flow?

Characteristics of Fluids Characteristics of Fluids The principal difference in the mechanical behavior of fluids compared to solids is that when a shear stress is applied to a fluid it experiences a continuing and permanent distortion. Fluids offer no permanent resistance to shearing, and they have elastic properties only under direct compression: in contrast to solids which have all three elastic moduli, fluids possess a bulk modulus only. Thus, a fluid can be defined unambiguously as a material that deforms continuously and permanently under the application of a shearing stress, no matter how small. This definition does not address the issue of how fast the deformation occurs and as we shall see later this rate is dependent on many factors including the properties of the fluid itself. The inability of fluids to resist shearing stress gives them their characteristic ability to change shape or to flow; their inability to support tension stress is an engineering assumption, but it is a well-justified assumption because such stresses, which depend on intermolecular cohesion, are usually extremely small..... Because fluids cannot support shearing stresses, it does not follow that such stresses are nonexistent in fluids. During the flow of real fluids, the shearing stresses assume an important role, and their prediction is a vital part of engineering work. Without flow, however, shearing stresses cannot exist, and compression stress or pressure is the only stress to be considered (Elementary Fluid Mechanics, 7th edition, by R.L. Street, G.Z. Watters and J.K. Vennard, John Wiley \& Sons, 1996). So we see that the most obvious property of fluids, their ability to flow and change their shape, is precisely a result of their inability to support shearing stresses. Flow is possible without a shear stress, since differences in pressure will cause a fluid lump to experience a resultant force and produce an acceleration, but when a fluid is deforming its shape, shearing stresses must be present. With this definition of a fluid, we can recognize that certain materials that look like solids are actually fluids. Tar, for example, is sold in barrel-sized chunks which appear at first sight to be the solid phase of the liquid which forms when the tar is heated. However, cold tar is also a fluid. If a brick is placed on top of an open barrel of tar, we will see it very slowly settle into the tar. It will continue to settle as time goes by --- the tar continues to deform under the applied load --- and eventually the brick will be engulfed by the tar. Even then it will continue to move downwards until it reaches the bottom of the barrel. Glass is another substance that appears to be solid, but is actually a fluid. The glass flows under the action of its own weight. If you measure the thickness of a very old glass pane you would find it to be larger at the bottom than at the top of the pane. This deformation happens very slowly because the glass has a very high viscosity, and the results can take centuries to become obvious. Another example: silly putty behaves like an elastic body when subject to rapid stress (it bounces like a ball) but it has fluid behavior under a slowly acting stress (it flows like a fluid under its own weight).


What is described as an ionized gas with approximately equal numbers of positive and negative charges?

Plasma | Article about plasma by The Free Dictionary Plasma | Article about plasma by The Free Dictionary http://encyclopedia2.thefreedictionary.com/plasma Related to plasma: Plasma tv , Plasma Chemistry , Plasma display plasma, in physics, fully ionized gas of low density, containing approximately equal numbers of positive and negative ions (see electron electron, elementary particle carrying a unit charge of negative electricity. Ordinary electric current is the flow of electrons through a wire conductor (see electricity). The electron is one of the basic constituents of matter. ..... Click the link for more information.  and ion ion, atom or group of atoms having a net electric charge. Positive and Negative Electric Charges A neutral atom or group of atoms becomes an ion by gaining or losing one or more electrons or protons. ..... Click the link for more information. ). It is electrically conductive and is affected by magnetic fields. The study of plasma, called plasma physics, is especially important in research efforts to produce a controlled thermonuclear reaction (see nuclear energy nuclear energy, the energy stored in the nucleus of an atom and released through fission, fusion, or radioactivity. In these processes a small amount of mass is converted to energy according to the relationship E = mc2, where E is energy, m ..... Click the link for more information. ). Such a reaction requires extremely high temperatures; it has been computed that a temperature of about 10 million degrees Celsius would be needed to initiate the reaction between deuterium and tritium. By passing a very high electric current through plasma great heat is produced and, simultaneously, an electromagnetic field is created, causing the plasma to withdraw from the walls of its container. The contraction of the plasma, called the pinch effect, prevents the container from being destroyed, but the effect may become unstable too quickly for the fusion reaction. The properties of plasma are distinct from those of the ordinary states of matter states of matter, forms of matter differing in several properties because of differences in the motions and forces of the molecules (or atoms, ions, or elementary particles) of which they are composed. ..... Click the link for more information. , and for this reason many scientists consider plasma a fourth state of matter. Interstellar gases, as well as the matter inside stars, are thought to be in the form of plasma, thus making plasma a common form of matter in the universe. See also condensate condensate, matter in the form of a gas of atoms, molecules, or elementary particles that have been so chilled that their motion is virtually halted and as a consequence they lose their separate identities and merge into a single entity. ..... Click the link for more information. . Plasma (physics) The field of physics that studies highly ionized gases. Plasma is a gas of charged and neutral particles which exhibits collective behavior. All gases become ionized at sufficiently high temperatures, creating what has been called a fourth state of matter, together with solids, liquids, and gases. It has been estimated that more than 99% of the universe is in the plasma state. On the Earth, plasmas are much less common. Lightning is a familiar natural manifestation, and fluorescent lights are a practical application. Plasma applications and studies make use of an enormous range of plasma temperatures, densities, and neutral pressures. They extend from plasma processing applications at relatively low temperatures (such as plasma etching of semiconductor chips at low pressure, or plasma cutting torches at atmospheric pressure) to studies of controlled fusion at very high temperatures. Plasma physics is a many-body problem that can be described by a combination of Newton's laws and Maxwell's equations. The charged particles in plasmas are usually ions, both positive and negative, and electrons. Plasmas are normally quasineutral; that is, the net positive ion charge density approximately equals the net negative charge density e


What name is given to the very serious chain of events which can follow the failure of the cooling system in a nuclear reactor?

THE FEARSOME REACTOR MELTDOWN ACCIDENT next=> THE FEARSOME REACTOR MELTDOWN ACCIDENT Technologies are normally developed by entrepreneurs whose primary goal is making money. If the technology is successful, the entrepreneurs prosper as a new industry develops and thrives. In the process, the environmental impacts of this new technology are the least of their concerns. Only after the public revolts against the pollution inflicted upon it does the issue of the environment come into the picture. At that point an adversarial relationship may develop, with the government serving to protect the public at the expense of the industry. Coal-burning technologies have been an excellent example of this development process. With nuclear energy, everything was to be entirely different. It was conceived and brought into being by the world's greatest scientists. They banded together to obtain government support; the highly publicized letter from Albert Einstein to President Roosevelt in 1941 was a key element in that process. Their motivation was entirely idealistic. None of them thought about making money, and there was no mechanism for them to do so. Their first objective was to save the world from the hideous Hitler, and after World War II it was to protect freedom and democracy through military strength. But from the beginning of the project in the early 1940s, the scientists always felt strongly that this new technology, developed at government expense, would provide great benefits to mankind. Distinguished scientists like Henry Smythe and Glenn Seaborg held high positions of power all the way up until the early 1970s, and through them many of the greatest and most idealistic scientists, like Enrico Fermi, Eugene Wigner, and Hans Bethe, exerted great influence on the course of events. Directly or indirectly, hundreds of scientists were involved in guiding our national nuclear energy program. They set up national laboratories of unprecedented size in the New York (Brookhaven), Chicago (Argonne), and San Francisco (Berkeley, Livermore) areas and at the wartime development sites in Oak Ridge, Tennessee and Los Alamos, New Mexico. They arranged for an unprecedented level of financial support for research in universities where most of the scientists were based. Their objectives went far beyond development of nuclear technology, and included seeking a thorough understanding of the environmental effects. Their approach ran the gamut from the most basic research to the most practical applications. The government's side of this enterprise was run by the Atomic Energy Commission (AEC). The AEC was set up at the behest of scientists to remove nuclear energy development from military control. Prominent scientists served as commissioners, often as chairmen. It's General Advisory Committee, made up of some of the nation's most distinguished scientists, exerted very strong influence. The AEC was monitored by the Congressional Joint Committee on Atomic Energy, which included some of the most powerful senators and representatives. A spirit of close cooperation reigned throughout. The goal of all was to provide humankind with the blessings of nuclear energy as expeditiously as possible. There was a general understanding among all concerned that the scientists had paid their dues  they had given the government's military nuclear weapons, nuclear submarines, and a host of other goodies  and that their new technology was to serve humanity under the guidance of this research enterprise. Government also recognized that this enterprise, in the long run, would serve the public interest, and continues to support it to this day. A recent well-publicized element of that program is the multibillion dollar superconducting supercollider accelerator to be constructed in Texas to study the fundamental nature of matter, with no practical applications in sight. Use of nuclear energy to generate electricity was a very important part of this research and development program. In order to promot


Which electronic device magnifies the strength of a signal?

Audio and sound engineer's glossary of terms. | Testing1212   Absorption Short for the term Acoustical Absorption (quality of a surface or substance to take in, not reflect, a sound wave). AC 1)  Abbreviation for alternating current. 2)  An abbreviation of the term Alternating Current (electric current which flows back and forth in a circuit; all studio signals running through audio lines are AC). Acoustic/Acoustical Having to do with sound that can be heard by the ears. AcousticsThe behaviour of sound and its study. The acoustics of a room depend on its size and shape and the amount and position of sound-absorbing and reflecting material. Acoustic Amplifier The portion of the instrument which makes the vibrating source move more air or move air more efficiently; this makes the sound of the instrument louder. Examples of acoustic amplifiers include: 1) The body of an acoustic guitar, 2) The sounding board of a piano, 3) The bell of a horn and 4) The shell of a drum. Acoustic Echo Chamber A room designed with very hard, non-parallel surfaces and equipped with a speaker and microphone; dry signals from the console are fed to the speaker and the microphone will have a reverberation of these signals that can be mixed in with the dry signals at the console. Action In guitar playing, action refers to how far the strings sit off of the guitar neck. When strings are close to the neck, it is referred to as “Low Action”. When the string sit far above the neck, it is called “High Action”. Guitars with low action are easier to play, but make sure they are not too close, or it could causing buzzing. Active Crossover Uses active devices (transistors, IC’s, tubes) and some form of power supply to operate. Active/Inactive Microphones Scientific definitions aside, active microphones generally sound better than inactive ones, but they generally cost more. They also require the use of either a battery or phantom power while inactive mics need only be plugged into the mic cord in order to work. In most playing situations, the subtle improvement in sound quality from an active mic isn’t worth the extra cost and hassle. One possible exception it the headset mic. Put simply, inactive headset mics just plain suck. Active headset mics put out a much stronger signal and feed back much less. A/D An abbreviation of Analog to Digital Conversion (the conversion of a quantity that has continuous changes into numbers that approximate those changes), or Analog to Digital Converter. ADAT A trademark of Alesis Corporation designating its modular digital multitrack recording system released in early 1993. ADSR The letters A, D, S &R are the first letters of: Attack, Decay, Sustain and Release. These are the various elements of volume changes in the sounding of a keyboard instrument. AES An abbreviation of Audio Engineering Society. AES/EBU Professional Interface A standard for sending and receiving digital audio adopted by the Audio Engineering Society and the European Broadcast Union. Aliasing A sampler mis-recognizing a signal sent to it that is at a frequency higher than the Nyquist Frequency. Upon playback, the system will provide a signal at an incorrect frequency (called an alias frequency). Aliasing is a kind of distortion. Alternating Current Electric current which flows back and forth in a circuit. Ambience The portion of the sound that comes from the surrounding environment rather than directly from the sound source. Ambient Field A term with the same meaning as the term Reverberant Field (the area away from the sound source where the reverberation is louder than the direct sound). Ambient Micing Placing a microphone in the reverberant field (where the reverberation is louder than the direct sound) so as to do a separate recording of the ambience or to allow the recording engineer to change the mix of direct to reverberant sound in recording. Amp 1) An abbreviation of the term Amplifier (A device which increases the level of an electrical signal. 2) An abbreviation of Ampere (the unit of current). 3) An abbreviation of amplitude (the height of a


What was the name of the unit of heat now replaced by the joule?

Units of Heat - <i>BTU, Calorie and Joule</i> The most common units for heat are BTU (Btu) - British Thermal Unit - also known as a "heat unit" in United States Calorie BTU - British Thermal Unit The unit of heat in the imperial system - the BTU - is the amount of heat required to raise the temperature of one pound of water through 1oF (58.5oF - 59.5oF) at sea level (30 inches of mercury). 1 Btu (British thermal unit) = 1055.06 J = 107.6 kpm = 2.931 10-4 kWh = 0.252 kcal = 778.16 ft.lbf = 1.0551010 ergs = 252 cal = 0.293 watt-hours An item using one kilowatt-hour of electricity generates 3412 Btu. one hundred thousand (105) Btu are called a therm Calorie A calorie is commonly defined as the amount of heat required to raise the temperature of one gram of water 1oC the kilogram calorie, large calorie, food calorie, Calorie (capital C) or just calorie (lowercase c) is the amount of energy required to raise the temperature of one kilogram of water by one degree Celsius 1 calorie (cal) = 1/860 international watthour (Wh) 1 kcal = 4186.8 J = 426.9 kp m = 1.163 10-3 kWh = 3.088 ft lbf = 3.9683 Btu = 1000 cal Be aware that alternative definitions exists - in short:  Thermochemical calorie   International Steam Table calorie (1929) International Steam Table calorie (1956) IUNS calorie (Committee on Nomenclature of the International Union of Nutritional Sciences) The calorie is outdated and commonly replaced by the SI-unit Joule. Joule The unit of heat in the SI-system the Joule is a unit of energy equal to the work done when a force of one newton acts through a distance of one meter 4.184 joule of heat energy (or one calorie) is required to raise the temperature of a unit weight (1 g) of water from 0oC to 1oC, or from 32oF to 33.8oF 1 J (Joule) = 0.1020 kpm = 2.778 10-7 kWh = 2.389 10-4 kcal = 0.7376 ft.lbf = 1 kg.m2/s2 = 1 watt second = 1 Nm = 9.478 10-4 Btu Heating - Heating systems - capacity and design of boilers, pipelines, heat exchangers, expansion systems and more Thermodynamics - Effects of work, heat and energy on systems Sponsored Links Heat Storage in Materials - Energy stored as sensible heat in materials Specific Heat of common Substances - Specific heat of materials like wet mud, granite, sandy clay, quartz sand and more Gases - Ratios of Specific Heat - Ratios of specific heat for gases in constant pressure and volume processes Heat, Work and Energy - Heat, work and energy tutorial - essentials as specific heat Specific Heat - Specific Heat is the amount of heat required to change a unit mass of a substance by one degree in temperature Sponsored Links en: heat units btu calorie joule es: unidades de calor por efecto Joule calorías btu de: Wärmeeinheiten btu Kalorien Joule Search the Engineering ToolBox


What does c represent in the equation e = mc*2?

What is the significance of E = mc2? And what does it mean? - Scientific American Scientific American Advertisement | Report Ad Ronald C. Lasky, director of the Cook Engineering Design Center at Dartmouth College, explains the significance behind this hallowed equation: It is the most famous equation in the world. Many can recite it—and attribute it to Albert Einstein—but few know its significance. It tells us that mass and energy are related, and, in those rare instances where mass is converted totally into energy, how much energy that will be. The elegance with which it ties together three disparate parts of nature—energy, the speed of light and mass—is profound. Here is where the equation of all equations comes from: It was known for some time before Einstein's insights that electromagnetic radiation (light, for example) possessed momentum. This quality of radiation is small in magnitude—after all, you needn't worry about being knocked over by sunlight—but easily measurable. Applying an understanding of light's momentum within a little thought experiment, it is possible to see how E = mc2 comes about. Consider a cubic hollow box at rest in space with sides of length D and a mass of M. This box is also symmetrical in its mass distribution. One of the faces inside the box is coated with a fluorescing material, and, at a given moment, a photon (i.e., a particle of light) is emitted from that material, perpendicular to its surface. The momentum of this photon causes the box to move in the opposite direction as the photon, and it continues to move until the photon hits the opposite wall. During this time the box moves a very small distance, Δx. Image: RONALD LASKY Newton's laws of mechanics tell us that the center of mass cannot move, because the box has not been acted upon by an outside force. However, in order to keep the center of mass constant, since the box has moved, some mass must have been transferred from the fluorescing side of the box to the absorbing side in the process of generating the photon and its striking the opposite side. Therefore the photon must have a mass, m. So the photon, which also possesses energy E, is emitted from the fluorescing side of the box. Its momentum, Pphoton, is equal to its energy divided by the speed of light: Pphoton = E / c. The photon will impart this momentum to the box, causing the box to move a small distance, Δx, during the time, t, in which the photon travels to the opposite side of the box. The momentum of the box, Pbox, is also equal to its mass, M, times the velocity, vbox, at which it moves before the photon strikes its target. (Note: The box loses the photon's mass, m, during this process, but this slight loss can be neglected here.) Hence: Pphoton = Pbox = E / c = Mvbox Then vbox = E / cM (1) We can also determine the time it takes for the photon to travel across the box: it is equal to the length, between parallel faces, of the box (which is D), minus the amount the box moved in the opposite direction (Δx), divided by the speed of light, c. (The target will essentially have moved a slight distance closer, meaning the photon did not have to travel the full distance D.): t = (D - Δx) / c


What is a cylindrical coil of wire in which a magnetic field is created when an electric current is passed though it?

electromagnetism - Why does electricity flowing through a copper coil generate a magnetic field? - Physics Stack Exchange Why does electricity flowing through a copper coil generate a magnetic field? up vote 4 down vote favorite Can some one please explain to me why electricity flowing though a copper coil generates a magnetic field or where I could possibly find that information? Are there other materials that produce a magnetic field when a current is run through them in a different shape? Thanks! up vote 4 down vote accepted Can some one please explain to me why electricity flowing though a  copper coil generates a magnetic field or where I could possibly find  that information? An electric current (a flow of electric charge) has an associated magnetic field regardless of the material (or space) the flow occurs in. This is a fundamental part of electromagnetism, rooted in observation, and quantified in Ampere's Law . I which to emphasize that this phenomenon is considered to be fundamental in nature, which means, there cannot be a "more" fundamental explanation (for, if there were, electromagnetism would not be fundamental). up vote 3 down vote This is a very-basic question. There are lot more things to digest than just that in EM..! All because of Maxwell equations ... Both Electric & Magnetic fields are inter-dependent (i.e.) One field requires another (or) one field produces another. The phenomenon is called Electromagnetism . For example, consider an electric charge at rest (static). It produces an electric field. But when the charge is in motion (current), a magnetic field is produced perpendicular to its direction of propagation. Say, If you pass current through a straight wire, magnetic field is formed around the wire in the form of circular rings (could affect compass or metal fillings nearby). On the other hand, you're passing current through a circular spring-like thing (commonly, a coil) called solenoid, magnetic field is produced along its axis. Simply you could keep in mind that Magnetic field is produced by moving charges (current). This is an observed phenomena and it's explained by Maxwell. Your last question is "Ok to ask"... Yes, there are a lot of materials (mostly metals) that produce magnetic field when current flows through them. But, Shape is not at all "a matter". It's whether there's a change in the fields that matters...


Whose 'unified field theory' tried to explain the four fundamental forces in terms of a single, unified force?

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What diverges rays of light, if it is concave?

Ray Diagrams - Concave Mirrors Reflection and the Ray Model of Light - Lesson 3 - Concave Mirrors Ray Diagrams - Concave Mirrors Spherical Aberration The theme of this unit has been that we see an object because light from the object travels to our eyes as we sight along a line at the object. Similarly, we see an image of an object because light from the object reflects off a mirror and travel to our eyes as we sight at the image location of the object. From these two basic premises, we have defined the image location as the location in space where light appears to diverge from. Ray diagrams have been a valuable tool for determining the path taken by light from the object to the mirror to our eyes. In this section of Lesson 3, we will investigate the method for drawing ray diagrams for objects placed at various locations in front of a concave mirror. To draw these diagrams, we will have to recall the two rules of reflection for concave mirrors: Any incident ray traveling parallel to the principal axis on the way to the mirror will pass through the focal point upon reflection. Any incident ray passing through the focal point on the way to the mirror will travel parallel to the principal axis upon reflection. Earlier in this lesson, the following diagram was shown to illustrate the path of light from an object to mirror to an eye. In this diagram five incident rays are drawn along with their corresponding reflected rays. Each ray intersects at the image location and then diverges to the eye of an observer. Every observer would observe the same image location and every light ray would follow the law of reflection. Yet only two of these rays would be needed to determine the image location since it only requires two rays to find the intersection point. Of the five incident rays drawn, two of them correspond to the incident rays described by our two rules of reflection for concave mirrors. Because they are the easiest and most predictable pair of rays to draw, these will be the two rays used through the remainder of this lesson   Step-by-Step Method for Drawing Ray Diagrams The method for drawing ray diagrams for concave mirror is described below. The method is applied to the task of drawing a ray diagram for an object located beyond the center of curvature (C) of a concave mirror. Yet the same method works for drawing a ray diagram for any object location. 1. Pick a point on the top of the object and draw two incident rays traveling towards the mirror. Using a straight edge, accurately draw one ray so that it passes exactly through the focal point on the way to the mirror. Draw the second ray such that it travels exactly parallel to the principal axis. Place arrowheads upon the rays to indicate their direction of travel.     2. Once these incident rays strike the mirror, reflect them according to the two rules of reflection for concave mirrors. The ray that passes through the focal point on the way to the mirror will reflect and travel parallel to the principal axis. Use a straight edge to accurately draw its path. The ray that traveled parallel to the principal axis on the way to the mirror will reflect and travel through the focal point. Place arrowheads upon the rays to indicate their direction of travel. Extend the rays past their point of intersection.   3. Mark the image of the top of the object. The image point of the top of the object is the point where the two reflected rays intersect. If your were to draw a third pair of incident and reflected rays, then the third reflected ray would also pass through this point. This is merely the point where all light from the top of the object would intersect upon reflecting off the mirror. Of course, the rest of the object has an image as well and it can be found by applying the same three steps to another chosen point. (See note below .)     4. Repeat the process for the bottom of the object. The goal of a ray diagram is to determine the location, size, orientation, and type of image that is formed by the concave mirror. Typically, this requires determining where the image of t


What can be expressed as the number of cycles of a vibration occurring per unit of time?

Frequency - definition of frequency by The Free Dictionary Frequency - definition of frequency by The Free Dictionary http://www.thefreedictionary.com/frequency n. pl. fre·quen·cies 1. The property or condition of occurring at frequent intervals. 2. Mathematics & Physics The number of times a specified periodic phenomenon occurs within a specified interval, as: a. The number of repetitions of a complete sequence of values of a periodic function per unit variation of an independent variable. b. The number of complete cycles of a periodic process occurring per unit time. c. The number of repetitions per unit time of a complete waveform, as of an electric current. 3. Statistics [Latin frequentia, multitude, from frequēns, frequent-, crowded, numerous, frequent.] frequency n, pl -cies 1. the state of being frequent; frequent occurrence 2. the number of times that an event occurs within a given period; rate of recurrence 3. (Mathematics) physics the number of times that a periodic function or vibration repeats itself in a specified time, often 1 second. It is usually measured in hertz. Symbol: ν or f 4. (Statistics) statistics a. the number of individuals in a class (absolute frequency) b. the ratio of this number to the total number of individuals under survey (relative frequency) 5. (Biology) ecology a. the number of individuals of a species within a given area b. the percentage of quadrats that contains individuals of a species Also called (for senses 1, 2): frequence [C16: from Latin frequentia a large gathering, from frequēns numerous, crowded] fre•quen•cy 1. Also, fre′quence. the state or fact of being frequent; frequent occurrence. 2. rate of occurrence. 3. Physics. a. the number of periods or regularly occurring events of any given kind in a unit of time, usu. one second. b. the number of cycles or completed alternations per unit time of a wave or oscillation. Symbol: F; Abbr.: freq. 4. Math. the number of times a value recurs in a unit change of the independent variable of a given function. 5. Statistics. the number of items occurring in a given category. [1545–55; < Latin] fre·quen·cy (frē′kwən-sē) 1. Physics The number of complete cycles of a wave, such as a radio wave, that occur per second. See more at wave . 2. Mathematics The ratio of the number of occurrences of some event to the number of opportunities for its occurrence. Frequency (See also DURATION , TIME .) once in a blue moon Very rarely. A blue moon occurs when there is a full moon twice in the same month, an unusual event, but one that takes place from time to time. rare as hen’s teeth See scarce as hen’s teeth, ABSENCE . when two Fridays come together Never. Since two Fridays never come together, this expression is usually used as a sarcastic quip when one is asked when he intends to do something of an onerous nature such as complete a project, pay back a personal loan, or the like. frequency Number of cycles or waves per second. ThesaurusAntonymsRelated WordsSynonymsLegend: Noun 1. frequency - the number of occurrences within a given time period; "the frequency of modulation was 40 cycles per second"; "the frequency of his seizures increased as he grew older" audio frequency , audio - an audible acoustic wave frequency radio frequency - an electromagnetic wave frequency between audio and infrared infrared , infrared frequency - the infrared region of the electromagnetic spectrum; electromagnetic wave frequencies below the visible range; "they could sense radiation in the infrared" wave number - the reciprocal of the wavelength of a wave attendance - the frequency with which a person is present; "a student's attendance is an important factor in her grade" count per minute , counts/minute - frequency per minute sampling frequency - (telecommunication) the frequency of sampling a continuously varying signal rate - a magnitude or frequency relative to a time unit; "they traveled at a rate of 55 miles per hour"; "the rate of change was faster than expected" 2. frequency - the ratio of the number of observations in a statistical category to the total number


What is the product of the mass of a body and its linear velocity?

What is the difference between force (F=MA) and momentum (mass * velocity)? - Quora Quora Written May 2, 2015 Formula wise, you just said it. By definition, momentum refers to the quantity of motion that an object has. And the rate of change of that momentum is defined as the force. Written May 6, 2015 Force and momentum are two concepts that are used in mechanics to describe statics or dynamics of bodies. Both force and momentum are vectors.  Force is an external cause, while momentum is an internal property of matter. A force is required to change the momentum of any object. The force on an object can be defined as the change of momentum per unit time.  The definition of force is “any influence that causes or attempts to cause a free body to undergo a change in the acceleration or the shape of the body.” There are two main types of forces  - contact forces and field forces. Contact forces are forces that are used in everyday incidents such as pushing or pulling an object. Field forces include gravitational force, magnetic force, and electric force. Forces such as static friction, surface tension, and reactive forces are all responsible for keeping the objects in static conditions. Forces such as gravitational force, electrical force, and magnetic force are all responsible for keeping the world and everything in the universe together. Momentum is a measurement of the inertia of an object. It is divided into two main types. One is the linear momentum, and the other is the angular momentum. Linear momentum is defined as the product of the mass and velocity of the object. Angular momentum is defined as the product of moment of inertia and angular velocity of the object. Both these are measurements of the current inertia of the system. Angular momentum is related to the rotation or revolution of matter. It is, in effect, a measure of the quantity of rotation of a system of matter, taking into account its mass, rotations, motions and shape.  Linear momentum is also a conserved quantity, meaning that if a closed system is not affected by external forces, its total linear momentum cannot change. This fact, known as the law of conservation of momentum, is implied by Newton's Laws of Motion. A change of momentum always requires a net force or torque acting upon the object. Momentum is a relativistic variant. Written Feb 17, 2016 Momentum measures the 'motion content' of an object, and is based on the product of an object's mass and velocity. Momentum doubles, for example, when velocity doubles. Similarly, if two objects are moving with the same velocity, one with twice the mass of the other also has twice the momentum. Force, on the other hand, is the push or pull that is applied to an object to CHANGE its momentum. Newton's second law of motion defines force as the product of mass times ACCELERATION (vs. velocity). Since acceleration is the change in velocity divided by time, you can connect the two concepts with the following relationship: force = mass x (velocity / time) = (mass x velocity) / time = momentum / time Multiplying both sides of this equation by time: force x time = momentum


Which quantity has direction as well as magnitude?

How does change of direction change the velocity? - Quora Quora Written May 10, 2016 Velocity is a vector quantity. It has both magnitude as well as direction. When we say that velicity changes, there can be three conditions: Only the magnitude  changes (what we call speed) and direction remains the same. Eg. A car moving on a straight road applies breaks. Only the direction changes and the magnitude remains constant. Eg. A car moves on a circular path with constant speed. Both the direction and the magnitude changes. Eg. A car moving along a curved path with some tangential acceleration. 367 Views Related Questions


What is the SI unit of magnetic flux density, named after a Croatian electrical engineer?

Enter a value into either text box and select units using the drop-down boxes. = What is Magnetic Flux Density? Magnetic flux density is the amount of magnetic flux per unit area of a section that is perpendicular to the direction of flux. It is also sometimes known as "magnetic induction" or simply "magnetic field". It can be thought of as the density of the magnetic field lines - the closer they are together, the higher the magnetic flux density. Mathematically it is represented as B = Φ/A where B is magnetic flux density in teslas (T), Φ is magnetic flux in webers (Wb), and A is area in square meters (m2).  The SI unit for magnetic flux density is the tesla which is equivalent to webers per square meter. The unit was named in 1960 after the Serbian-American electrical engineer Nikola Tesla. Bookmark this page in your browser using CtrlÂ andÂ d or using one of these services: (opens in new window)