Physics -- Units and Concepts: Acceleration

Now this is a more unfamiliar concept. It is the rate of change of speed.

If you start from a standstill, then begin to walk so that after 1 second you go at 1 m/s and keep increasing your speed so that another second later you go at 2 m/s, then 3 m/s and so on until after 10 seconds you go at 10 m/s, you have accelerated. Your speed has constantly gone up. It has gone up by 1 m/s every second. It has changed by 1 metre per second per second. Pronounce that again: you accelerated at 1 metre-per-second per second. And so the unit of acceleration is 1 m/s². Forget what the "square seconds" might mean, just think of it as a change of speed per second. There are not many everyday uses for measuring acceleration, with one noteable exception: accelerometers trigger airbags in car crashes.

next planned revision: 2005-06-01