Q & A: Definitions of acceleration

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Q:
why, when studying force, does acceleration= force divided by mass, and other times acceleration= final v.- initial v. divided by time.
- abigail
A:
Hi Abigail,

That is an excellent question.   The answer is that the acceleration in the first case is a "Dynamic" phenomenon, i.e., it is the response of an object due to an applied external motive force.  The acceleration in the second case is called "Kinematic" and is simply the mathematical definition of acceleration being equal to the rate of change of velocity.

LeeH

In other words, it's the same acceleration, but one formula says what acceleration means and the other tells you how to calculate what the value will be when the forces on an obect are known. Mike W.

(published on 03/09/08)