Force is equal to the derivative of linear momentum with respect to time. While force is usually defined as being equal to the product of mass and acceleration, i.e., F = ma, a more correct definition is F = dp/dt, where p is linear momentum.
The F = dp/dt definition becomes very important in special relativity. Momentum, p, is equal to the product of mass and velocity, so p = mv. At speeds much lower than the speed of light, we can say dp/dt = d/dt(mv) = m*dv/dt = ma, because mass is constant and acceleration is the time derivative of velocity. However, at speeds on the same order of magnitude as the speed of light, m is not constant but instead has a dependency on v. F = ma no longer holds true, but F = dp/dt remains valid.
2007-03-19 08:17:56
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answer #1
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answered by DavidK93 7
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Either - the bigger the force applied, the higher the momentum.
or - the higher the linear momentum, the higher the force needed to stop.
2007-03-19 09:04:37
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answer #2
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answered by R.E.M.E. 5
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The change of momenum of an object as the consequence of force applied to it can be found as follows:
∆p = F∆t
Compare this with the change of kinetic energy of an object:
∆E = F∆x
From this we can see that
∆E/∆p = dE/dp = ∆x/∆t = dx/dt = v
This is a general result true in classical, relativistic, and quantum mechanics, and it's even true for light, as E = pc. It's worth keeping in mind.
2007-03-19 08:40:06
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answer #3
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answered by Scythian1950 7
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F= m a
F =m delta V/delta t
F delta V = m delta t
impuls = momentum
2007-03-19 12:15:05
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answer #4
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answered by Anonymous
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tension is rather the fee of replace of momentum with admire to time.. F= (mv-mu)/t this provides F=ma because of the fact the mass is persevering with and the differential of speed is acceleration (with admire to time)
2016-10-19 02:25:47
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answer #5
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answered by Anonymous
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