acceleration in a circle

Question

If something is going around in a circle, how come it is accelerating, even if the speed is the same? It seems like the acceleration should be 0 since the speed is not increasing.

Answer 1

If you take a string and attached an object to it, like a pencil, and then swing it in a circle, something odd happens. You feel it pull away from you, even if you are turning at a constant speed. That net force is from you accelerating the pencil in a different direction (angular acceleration). Acceleration can be both linear and angular.

Answer 2

Acceleration is the rate of change in velocity. Velocity is basically speed, but in a certain direction. So, as an object goes in a circle, it is constantly changing direction, right? You could say it is changing velocities. So, because acceleration is the rate of change in velocity, it is accelerating, even though it might be going at a constant speed.

 

Please comment, if this doesn't make sense. I can explain it further if you still don't get it.