posted by John .
The wheel is attached to an electric generator and the rotation rate drops from 290 to 230 in 3.5 . What is the average power output?
To start off, I will assume that 290 and 230 are in terms of rpm.
Inertia of disc= 1/2*m*r^2
W must be in terms of rad/s, so multiply each rpm term by 2pi/30.
Divide Kf-Ki by t and you will get average power.