Question

A young girl (mass = 35.0 kg) is standing on a raft floating on a pond (initial speed = 0). The raft's length is 4.00 m; it is made of wood (density = 700 kg/m³) and has a mass of 267 kg. The density of water is 1000 kg/m³.

            a.         Before the girl gets on the raft, what fraction of its volume is below the water?

            b.         The girl and the raft were initially at rest (relative to the water), with the girl at the left end. Now, she walks to the other end of the raft at a constant speed of .500 m/s,

                        measured relative to the water. What is the speed of the raft relative to the water? (Ignore viscosity of water.)

            c.         How much work does the girl do in setting the raft and herself into motion?

Answer 1