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Rotational motion

Problem 1
A wheel of radius 0.20 meters is mounted on a frictionless horizontal axis. The rotational inertia of the wheel about the axis is 0.050 kgm^2. A massless cord wrapped around the wheel is attached to a 2.0 kg block that slides on a horizontal frictionless surface. If a horizontal force of magnitude P=3.0 N is applied to the block as shown in the problem 1 attachment, what is the magnitude of the angular acceleration of the wheel? Assume the string does not slip on the wheel.

Problem 2
A 32.0 kg wheel, essentially, a thin hoop with radius 1.20 meters, is rotating a 280rev/min. It must be brought to a stop in 15.0 sec. How much work must be done to stop it? And what is the required average power?


Solution Preview

Hello and thank you for submitting your problem to BrainMass.
Please see the attached file.
<br>I solved problem 1 using two methods.
<br>The first method uses conservation of energy while the second method uses Newton's second law. Needless to say, the result is identical using both methods.
<br>Before you look at the solution let ...

Solution Summary

The solution shows two approaches to the solve the problem and shows that the end result is the same.