5.6 Review Questions

1a. Work Done = PE gained = mgh = (60 kg)(10 m/s/s)(6 m) = 3600 J
1b. Power = Work/time = 3600 J / 45 s = 80 W

2. 60 W = 60 J/s, 10 hours = 36,000 s.  60 J/s x 36,000 s = 216,000 J

3.  Work Done = KE gained = 1/2 mv^2 = 1/2(750 Kg)(20 m/s  ^2) = 150,000 J
Power = Work / time = 150,000 J / 15.0 s = 10,000 W

4.  A truck can do more work in the same amount of time or the same work in less time than a person.