(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A uniform solid disk of radius (r) 6.71 m and mass (m) 38 kg is free to rotate on a frictionless pivot through a point on its rim. If facing the disk, the pivot is on the left side. The disk is then released. What is the speed of the center of mass when the disk reaches a position such that the pivot is now at the top (lowest point in swing)?

What is the speed of the lowest point of the disk in said position?

Repeat part one for a uniform hoop.

2. Relevant equations

Looks like conservation of energy here. I know that the disk drops down one radius, so my initial energy was just mgr. At the bottom it has translational and rotational KE. .5mv^2 + .5Iw^2.

3. The attempt at a solution

Not sure, I'm looking for a step in the right direction. Probably need to use the parallel axis theorem somehow since it isn't rotating through the center?

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# Homework Help: Weird disk rotating on pivot

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