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Starting from rest, a 12-cm-diameter compact disk takes 3.0 s to reach its operating angular velocity of 2000 rpm. Assume that the angular acceleration is constant. The disk's moment of inertia is 2.5 x 10^-5 kg m^2. How much torque is applied to the disk? How many revolutions does it make before reaching full speed?

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you need to know the following equations inorder to do this calculation.

`omega = omega_0+alpha*t`

`tau= I*alpha`


For our question;

omega_0 = 0 because it starts from rest.

    omega = 2000/60*2*pi/3 = 69.813rad/s


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