Acceleration: Difference between revisions

Revision as of 14:36, 20 June 2005

Revision as of 00:46, 22 June 2005

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:<math>\mathbf{t}</math> is the time interval (s)

[[Transverse]] acceleration ([[perpendicular]] to velocity) causes change in direction. If it is constant in magnitude and changing in direction with the velocity, we get a [[circular motion]]. For this [[centripetal acceleration]] we have

:<math> \mathbf{a} = - \frac{v^2}{r} \frac{\mathbf{r}}{r} = - \omega^2 \mathbf{r}</math>

One common unit of acceleration is ''[[gee|g]]'', one ''g'' being the acceleration caused by the [[gravity]] of [[Earth]] at [[sea]] level at 45° [[latitude]] (Paris), or about 9.81 m/s&sup2;.

Accelerating acceleration or [[jerk]] is the rate of change of an object's acceleration over time. However, an acceleration of accelerating acceleration would not be distinguished in practice as it would be experienced merely as a different [[slope]] of accelerating acceleration.

In [[classical mechanics]], acceleration <math> a \ </math> is related to [[Force (physics)|force]] <math>F \ </math> and [[mass]] <math>m \ </math> (assumed to be constant) by way of [[Newton's laws of motion|Newton's second law]]:

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In special relativity, only [[inertial frame|inertial frames of reference]] (non-accelerated frames) can be used and are equivalent; general relativity considers all frames, even accelerated ones, to be equivalent.

With changing velocity, accelerated objects exist in warped space (as do those that reside in a gravitational field). Therefore, frames of reference must include a description of their local [[spacetime]] [[curvature]] to qualify as complete.

==See also==