2. Page 375, fig. 2

4. Page 374, fig. 1

6. Page 375, fig. 3

7. Page 376

10. A hydraulic lift exerts a force of 12,000 N to lift a car 2 m. How much work is done on the car?

11. W = F X D

12. A hydraulic lift exerts a force of 12,000 N to lift a car 2 m. How much work is done on the car? W = F X D = 12,000 N X 2 m

13. A hydraulic lift exerts a force of 12,000 N to lift a car 2 m. How much work is done on the car? W = F X D = 12,000 N X 2 m = 24,000 Nm

14. A hydraulic lift exerts a force of 12,000 N to lift a car 2 m. How much work is done on the car? W = F X D = 12,000 N X 2 m = 24,000 Nm = 24,000 J

15. You exert a force of 0.2 N to lift a pencil off the floor. How much work do you do if you lift it 1.5 m?

16. W = F X D

17. You exert a force of 0.2 N to lift a pencil off the floor. How much work do you do if you lift it 1.5 m? W = F X D = 0.2 N X 1.5 m

18. You exert a force of 0.2 N to lift a pencil off the floor. How much work do you do if you lift it 1.5 m? W = F X D = 0.2 N X 1.5 m = 0.3 Nm

19. You exert a force of 0.2 N to lift a pencil off the floor. How much work do you do if you lift it 1.5 m? W = F X D = 0.2 N X 1.5 m = 0.3 Nm = 0.3 J

20. Page 377, fig. 4

21. Page 378

25. Page 379, fig. 5

27. Page 379, fig. 6

30. Page 380, fig. 7

31. Page 381, fig. 8

33. Page 380, fig. 7

34. Page 382

35. You cut the lawn with a hand mower. You do 250,000 J of work to move the mower. If the work done by the mower in cutting the lawn is 200,000 J, what is the efficiency of the mower? E = W o WiWi E = 200,000 J 250,000 J E = 0.8 X 100% = 80%

36. You do 1,500 J of work using a hammer. The hammer does 825 J of work on a nail. What is the efficiency of the hammer? E = W o WiWi

37. You do 1,500 J of work using a hammer. The hammer does 825 J of work on a nail. What is the efficiency of the hammer? E = W o WiWi E = 825 J 1,500 J

38. You do 1,500 J of work using a hammer. The hammer does 825 J of work on a nail. What is the efficiency of the hammer? E = W o WiWi E = 825 J 1,500 J E = 0.55 X 100% = 55%

39. Suppose you left your lawn mower outdoors all winter. It's now rusty. Of your 250,000 J of work, only 100,000 J go to cutting the lawn. What is the efficiency of the machine now? E = W o WiWi

40. Suppose you left your lawn mower outdoors all winter. It's now rusty. Of your 250,000 J of work, only 100,000 J go to cutting the lawn. What is the efficiency of the machine now? E = W o WiWi E = 100,000 J 250,000 J

41. Suppose you left your lawn mower outdoors all winter. It's now rusty. Of your 250,000 J of work, only 100,000 J go to cutting the lawn. What is the efficiency of the machine now? E = W o WiWi E = 100,000 J 250,000 J E = 0.4 X 100% = 40%