# Angular acceleration

1. Mar 17, 2006

### elmariachi

I have a shaft with radius "r" running at a certain RPM. how can i determine the angular acceleration of the shaft. Do i need any other parameters as well? Can i say that the angular acceleration can be (w^2*r), w is the angular velocity, r being the radius.

thanks

2. Mar 17, 2006

### HungryChemist

is the "certain RPM" a constant? If so, change in angular velocity of time has to be zero.

3. Mar 17, 2006

### jf117

In fact, any time an RPM is given it is meant that the rotatory motion is uniform, i.e. the angular velocity is a constant and , therefore, the angular acceleration is zero. Perhaps the problem meant to ask the centripetal acceleration?

J