In physics terms, acceleration, *a*,
is the amount by which your velocity changes in a given amount
of time. Given the initial and final velocities, *v _{i}* and

In terms of units, the equation looks like this:

Distance per time squared? Don’t let that throw you. You end up
with time squared in the denominator because you divide velocity
by time. In other words, *acceleration* is
the rate at which your velocity changes, because rates have time
in the denominator. For acceleration, you see units of meters
per second^{2}, centimeters per second^{2},
miles per second^{2}, feet per second^{2}, or
even kilometers per hour^{2}.

It may be easier, for a given problem, to use units such as mph/s (miles per hour per second). This would be useful if the velocity in question had a magnitude of something like several miles per hour that changed typically over a number of seconds.

Say you become a drag racer in order to analyze your acceleration down the dragway. After a test race, you know the distance you went — 402 meters, or about 0.25 miles (the magnitude of your displacement) — and you know the time it took — 5.5 seconds. So what was your acceleration as you blasted down the track?

Well, you can relate displacement, acceleration, and time as follows:

and that’s what you want — you always work the algebra so that
you end up relating all the quantities you know to the one
quantity you *don’t* know.
In this case, you have

(Keep in mind that in this case, your initial velocity is 0 —
you’re not allowed to take a running start at the drag race!)
You can rearrange this equation with a little algebra to solve
for acceleration; just divide both sides by *t*^{2} and
multiply by 2 to get

Great. Plugging in the numbers, you get the following:

Okay, the acceleration is approximately 27 meters per second^{2}.
What’s that in more understandable terms? The acceleration due
to gravity, *g,* is
9.8 meters per second^{2}, so this is about 2.7 g’s —
you’d feel yourself pushed back into your seat with a force
about 2.7 times your own weight.

Copyright 2016 Computer Geek Services - Terms and Conditions