1. Jul 26, 2010

tee yeh hun

I got one question about it.

Why we cant use it as τ =Iα istead of F=mv^2/r ?

since both are forces about circular motion

Last edited: Jul 26, 2010
2. Jul 26, 2010

Staff: Mentor

They describe different aspects of circular motion.
This describes the centripetal (radial) force acting on an object that is moving in a circle at some speed.
This describes the torque necessary to give some object (with rotational inertia I) an angular acceleration.

If something moves in a circle at constant speed, then the angular acceleration is zero--no torque is needed. But there will be a centripetal force on the object.

3. Jul 26, 2010

thx ...