A 20 lb uniform disc A is pinned to a 4 lb uniform rod CB which is pinned to a 0.03106 slug collar C. C slides on a smooth vertical rod and the disc rolls without slipping. Determine: a) the angular acceleration ofA and the acceleration of C when released from rest and b)The velocity of B and C when the rod is horizontal.

Mary starts from her house, walks 80 meters south, and stops to chat with her aunt on the sidewalk. after chatting for a few minutes, she walks 125 meters to the west to meet a friend and then walks 45 meters north with her friend to a cafe for lunch. overall, she takes 10 minutes to do all this. what is mary’s average speed?