# Question on moments of inertia

I have a mechanics question that I can't seem to figure out. I've spent quite a bit of time on it but dont have much of an answer.

If anyone can help I would appreciate it.

Round objects are rolling without slipping down an inclined plane of height H above the horizontal. The box is sliding without friction down the slope. All round objects have the same radius R & the same M, which is also the mass of the box. The moments of intertia for the round objects are: Hoop: I = MR^2, Cylinder = I (1/2)MR^2, Sphere I = (2MR^2)/5. The 4 objects are released, one at a time, from the hiehg H. Which one arives at the bottom with the greatest speed? Why? Which arrives with the smallest speed? Why? What physical principle did you use to answer these questions?

The professor wants answers in words and not so much equations.

I would think the box would be the slowest. If I remember right, an object rotates faster if the mass is in the center instead of on the outside edges.

But Im really confused.

If anyone can help I would appreciate it.

Thanks,

Mike

Related Introductory Physics Homework Help News on Phys.org
jamesrc