# Physics

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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?

• Physics - ,

units???

• Physics - ,

To start off, I will assume that 290 and 230 are in terms of rpm.

Pave=(Kf-Ki)/t

t=3.2

K=1/2*I(inertia)*w(omega)^2

Inertia of disc= 1/2*m*r^2

W must be in terms of rad/s, so multiply each rpm term by 2pi/30.

Kf-Ki= (1/2)*(1/2*m*r^2)*(Wf^2-Wi^2)

Divide Kf-Ki by t and you will get average power.