## Thursday, May 2, 2013

### Acceleration

Last time we learned how kinematics is the study of measuring how things move.
We learned about distance, time and velocity.

There's another fun thing we can measure, called acceleration.

Imagine you are in a race car at the starting line.
As soon as the race starts you are going to speed up to go as fast as you can, until you cross the finish line.

How fast were you going right before the race started?
Your velocity was zero, (0 mph) because you weren't moving.

And by the time you crossed the finish line maybe you were going super fast,
so your velocity was 100 mph.

When we want to measure how fast you sped up, that's called acceleration.
We usually use the letter a for acceleration.

We're measuring how much velocity (v) changes over time (t).
Velocity is in miles per hour (mph) or meters per second (m/s).
Time is in hours (h) or seconds (s).

So m/s / s = m/s^2, meters per second per second or meters per second squared.

It might sound funny, but that's how we measure how fast we changed from one speed to another. (from: wikipedia - acceleration)