Question

7) A disk is initially spinning about its center at 17 rad/s counter-clockwise and a constant angular acceleration of 2.9 rad/s2 is applied to it clockwise. How many revolutions does it make before it stops?

Answer 1

The initial angular velocity of the disk is in the counter clockwise direction.

However, the angular acceleration of the disc is in the clockwise direction

Since the acceleration of the disc is constant, the angular motion of the disc is governed by the kinematics equations for uniformly accelerated motion. To find the angular distance covered by the disc before coming to rest we use

We know that

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