1. Work and Power Test Review Thurs May 23

2. Formulas: Take these down since they will not be on the test.

6. Units: If you do a problem and don’t include the units in an answer you get no crecit Work= Joules Power = Watts KE= Joules PE = Joules F= Newtons M= kg D= m

7. Format of Test a)10 True and False b)24 Multiple choice c)5 Math problems

8. Question 1 As the mass increases the kinetic energy increases.

9. Question 2 All forms of energy are just the same thing.

10. Question 3 Energy is measured in joules.

11. Question 4 In a car engine burning fuel produces heat.

12. Question 5 Light energy travels from the sun and is transformed to chemical energy by plants.

13. Question 6 On a swing the kinetic energy is the greatest at the lowest point.

14. Question 7 Energy doesn’t necessarily involve motion.

15. Question 8 Energy is the ability to do work. Energy is the ability to cause change.

16. Question 9 Raising an object increases its potential energy.

17. Question 10 Work is done when an object is moved and the force that causes the motion is in the same direction as the movement.

18. Question 11 A power problem.

19. Question 12 Kinetic energy = the energy of motion.

20. Question 13 During nuclear reactions mass is converted to energy.

21. Question 14 A kinetic energy problem.

22. Question 15 The formula for work is W=Fd or Work= force x distance.

23. Question 16 Joules are the units for work

24. Question 17 Gravitational potential energy is the energy of an object due to its position.

25. Question 18 If you double the velocity of an object its kinetic energy is quadrupled since the formula involves the square of the velocity. The square of two is four.

26. Question 19 Power is the rate at which work is done.

27. Question 20 Law of conservation of energy.

28. ‘ Question 21 questio Definiton of power.

29. Question 22 A work problem.

30. Question 23 When you wind a watch you are working with a spring inside the watch which involves elastic potential energy.

31. Question 24 Definition of power.

32. Question 25 A power problem.

33. Question 26 Calculate the work done in a situation

34. Question 27 The kinetic energy of an object increases as its velocity increases.

35. Question 28 Mechanical energy is the sum of the kinetic and potential energy of an object.

36. Question 29 A vehicle converts the chemical energy of the fuel into kinetic energy.

37. Question 30 A work problem.

38. Question 31 A kinetic energy problem. Remember the potential energy at the top equals the kinetic energy at the bottom.

39. Question 32 Find the object in a list that does not use electric energy

40. Question 33 Watts are the units of power.

41. Question 34 Definition of elastic potential energy.

42. Bubba picks up a 250 kg sack of grain and puts it on his shoulder 1.2 m above the ground. What is the potential energy of the grain? GivenWorkAnswer M=250 kg H=1.2 G= 9.8 W=PE PE=mgh PE= 250 (9.8) 1.2 2940 J

43. A 90-kg male gymnast does the iron cross 4.5 m above the floor. Find his potential energy. GivenWorkAnswer M=90 kg H=4.5 G= 9.8 W=PE PE=mgh PE= 90 (9.8) 4.5 3969 J

44. A 10-kg bicycle carrying a 90-kg guy is traveling at a speed of 7 m/s. What is the kinetic energy of the guy and the bicycle? GivenWorkAnswer

45. A ball weighs 7.6 N and can be kicked a distance of 1.5 m. What is the work applied to the soccer ball? GivenWorkAnswer F= 7.6 D= 1.5 W=Fd W= 7.6 (1.5) 11.4 J

46. How much work is applied to your backpack if 100 W of power are used for 25 seconds? GivenWorkAnswer P= 100 W T= 25 s P=W/t W=Pt W= 2500 2500 J