# Rotational Dynamics

1. Feb 11, 2008

### novicephysics

An electric-generator turbine spins at 3600 rpm. Friction is so small that it takes the turbine 10.0 min to coast to a stop. How many revolutions does it make wile stopping?

2. Feb 12, 2008

### blochwave

For these problems you can use the rotational versions of all your linear equations you've been using

So instead of d, you have theta, instead of v, angular velocity, and so on.

So the equation d=1/2at^2-Vi*t can be used but with the angle travelled in radians for d, angular acceleration for a, and initial angular velocity for Vi. That's not the particular equation you should use here though. This is similar to a problem where you know initial velocity and time, and want to find a. Then you can find d(which in this case is the total angle travelled in radians, so for example if it were like 6pi, the answer would be 3 revolutions)