Problem 7. (a) A uniform solid disk of radius R and mass M is free to rotate on a frictionless pivot through a point on its rim. If the disk

is released from the position indicated in the figure(the center of the disk is at the same height as the pivot), what is the linear speed of the center of mass when the disk reaches the position indicated by the dashed circle? Hint: do not forget that the disk is rotating about a point on its rim. It is not rotating about its center. You will need to use the parallel axis theorem (see your textbook) to determine the correct moment of inertia. (b)What is the linear speed of the lowest point on the disk in the dashed position? (c) Repeat part(a) for a uniform hoop instead of a disk.

Fig: 1

Fig: 2