Answer:

Explanation:
The angular acceleration is:


And the angular deceleration is:


The total number of revolutions is:



Thank you for posting your question here at brainly. Below is the solution:
Ke up top = 1/2*.25 *225
<span>gain of Pot energy = .25*9.81*1.2 </span>
<span>work input = (1/4)(2 pi *.6)*30 </span>
<span>so </span>
<span>sum of those 3 energies = </span>
<span>(1/2)(.25)v^2</span>