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Homework Help: Rotating Wheel Problem

  1. Apr 3, 2006 #1
    A grinding wheel is in the form of a uniform solid disk of radius 7.01 cm and mass 1.90 kg. It starts from rest and accelerates uniformly under the action of the constant torque of 0.591 Nm that the motor exerts on the wheel.

    (a) How long does the wheel take to reach its final rotational speed of 1190 rev/min?

    Take torque = I * angular acceleration
    I=. 5MR^2

    .591 = (.5*1.9*.0701^2)(a)

    So 1190/126.6 = 9.4 Seconds

    Is there a problem with the logic here?
  2. jcsd
  3. Apr 3, 2006 #2
    Acceleration is rad/s^2 while the velocity is given in rev/min. Otherwise there is no mistake.
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