Information about Nerve Impulse
In classical mechanics, an impulse is defined as the integral of a force with respect to time:
A simple derivation using Newton's second law yields:
As a result, an impulse may also be regarded as the change in momentum of an object to which a force is applied. The impulse may be expressed in a simpler form when both the force and the mass are constant:
where
However, it is often the case that one or both of these two quantities vary.
In the technical sense, impulse is a physical quantity, not an event or force. However, the term "impulse" is also used to refer to a fast-acting force. This type of impulse is often idealized so that the change in momentum produced by the force happens with no change in time. This sort of change is a step change, and is not physically possible. However, this is a useful model for certain purposes, such as computing the effects of ideal collisions, especially in game physics engines.
Impulse has the same units and dimensions as momentum (kg m/s = Nยทs).
- I is impulse (sometimes marked J),
- F is the force, and
- dt is an infinitesimal amount of time.
A simple derivation using Newton's second law yields:
As a result, an impulse may also be regarded as the change in momentum of an object to which a force is applied. The impulse may be expressed in a simpler form when both the force and the mass are constant:
where
- F is the constant total net force applied,
is the time interval over which the force is applied,
- m is the constant mass of the object,
- Δv is the change in velocity produced by the force in the considered time interval, and
- mΔv = Δ(mv) is the change in linear momentum.
However, it is often the case that one or both of these two quantities vary.
In the technical sense, impulse is a physical quantity, not an event or force. However, the term "impulse" is also used to refer to a fast-acting force. This type of impulse is often idealized so that the change in momentum produced by the force happens with no change in time. This sort of change is a step change, and is not physically possible. However, this is a useful model for certain purposes, such as computing the effects of ideal collisions, especially in game physics engines.
Impulse has the same units and dimensions as momentum (kg m/s = Nยทs).
See also
- specific impulse
- Wave-particle duality defines an impulse for waves. The preservation of momentum at a collision is then called phase matching. Applications include:
- Compton effect
- nonlinear optics
- Acousto-optic modulator
- Umklapp scattering
- electron phonon scattering
References
- Serway, Raymond A.; Jewett, John W. (2004). Physics for Scientists and Engineers, 6th ed., Brooks/Cole. ISBN 0-534-40842-7.
- Tipler, Paul (2004). Physics for Scientists and Engineers: Mechanics, Oscillations and Waves, Thermodynamics, 5th ed., W. H. Freeman. ISBN 0-7167-0809-4.
External links and references
Classical mechanics (commonly confused with Newtonian mechanics, which is a subfield thereof) is used for describing the motion of macroscopic objects, from projectiles to parts of machinery, as well as astronomical objects, such as spacecraft, planets, stars, and galaxies.
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INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) is detecting some of the most energetic radiation that comes from space. It is the most sensitive gamma ray observatory ever launched.
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In physics, force is an action or agency that causes a body of mass m to accelerate. It may be experienced as a lift, a push, or a pull. The acceleration of the body is proportional to the vector sum of all forces acting on it (known as net force or resultant force).
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time.
One view is that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence, and time itself is something that can be measured.
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One view is that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence, and time itself is something that can be measured.
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Infinitesimals have been used to express the idea of objects so small that there is no way to see them or to measure them. For everyday life, an infinitesimal object is an object which is smaller than any possible measure, whether we measure size, time, chemical concentration, etc.
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Newton's laws of motion are three physical laws which provide relationships between the forces acting on a body and the motion of the body, first compiled by Sir Isaac Newton.
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momentum (pl. momenta; SI unit kg m/s, or, equivalently, N•s) is the product of the mass and velocity of an object. For more accurate measures of momentum, see the section "modern definitions of momentum" on this page.
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step function if it can be written as a finite linear combination of indicator functions of half-open intervals. Informally speaking, a step function is a piecewise constant function having only finitely many pieces.
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A physics engine is a computer program that simulates Newtonian physics models, using variables such as mass, velocity, friction and wind resistance. It can simulate and predict effects under different conditions that would approximate what happens in real life or in a fantasy
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kilogram or kilogramme (symbol: kg) is the SI base unit of mass. The kilogram is defined as being equal to the mass of the International Prototype Kilogram (IPK), which is almost exactly equal to the mass of one liter of water.
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Metre per second (U.S. spelling: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector quantity which specifies both magnitude and a specific direction), defined by distance in metres divided by time in seconds.
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The newton (symbol: N) is the SI derived unit of force, named after Sir Isaac Newton in recognition of his work on classical mechanics.
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Definition
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second (SI symbol: s), sometimes abbreviated sec., is the name of a unit of time, and is the International System of Units (SI) base unit of time.
SI prefixes are frequently combined with the word second to denote subdivisions of the second, e.g.
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SI prefixes are frequently combined with the word second to denote subdivisions of the second, e.g.
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Specific impulse (usually abbreviated Isp) is a way to describe the efficiency of rocket and jet engines. It represents the impulse (change in momentum) per unit of propellant.
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In physics, Compton scattering or the Compton effect, is the decrease in energy (increase in wavelength) of an X-ray or gamma ray photon, when it interacts with matter.
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Nonlinear optics (NLO) is the branch of optics that describes the behaviour of light in nonlinear media, that is, media in which the polarization P responds nonlinearly to the electric field E of the light.
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acousto-optic modulator (AOM), also called a Bragg cell, uses the acousto-optic effect to diffract and shift the frequency of light using sound waves (usually at radio-frequency).
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Umklapp scattering (also U-process or Umklapp process) is an anharmonic phonon-phonon (or electron-phonon) scattering process creating a third phonon with a momentum k-vector outside the first Brillouin zone.
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phonon is a quantized mode of vibration occurring in a rigid crystal lattice, such as the atomic lattice of a solid.[1] The study of phonons is an important part of solid state physics, because phonons play a major role in many of the physical properties of solids,
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