A 60-kg woman stands on the back of a 6-m-long, 120-kg raft that is floating at rest in still water with no friction. The raft is 0.5 m from a fixed pier, as in Figure. 

(a) The woman walks to the front of the raft and stops. How far is the raft from the pier now? 

(b) While the woman walks, she maintains a constant speed of 3 m/s relative to the raft. Find the total kinetic energy of the system (woman plus raft), and compare with the kinetic energy if the woman walked at 3 m/s on a raft tied to the pier.

(c) Where does this energy come from, and where does it go when the woman stops at the front of the raft? 

(d) On land, the woman can put a lead shot 6 m. She stands at the back of the raft, aims forward, and puts the shot so that just after it leaves her hand, it has the same velocity relative to her as it does when she throws it from the ground. Where does the shot land?

Transcribed Image Text:

60 kg : 0.5 m : 120 kg