2 pt

1. Answer – must in Q form – V holds the final right for the answer Force Friction Grace under Pressure Blackout Steel Wheels 1pt 1 pt 1 pt 1pt 1 pt 2 pt 2 pt 2pt 2pt 2 pt 3 pt 3 pt 3 pt 3 pt 3 pt 4 pt 4 pt 4pt 4 pt 4pt 5pt 5 pt 5 pt 5 pt 5 pt

2. What is the SI unit for speed?

3. m/s ?

4. push or a pull that always acts on an object

5. What is force ?

6. the force of attraction between two objects

7. What is gravity ?

8. Name the two factors that determine speed

9. What are distance and time ?

10. A golf ball that is hit straight down the fairway hits the ground, and it rolls a long way. Why doesn't it continue to roll forever?

11. Friction eventually stops the ball

12. The force of gravity is greater between two objects that have what?

13. have greater masses ?

14. To produce change in motion, a force must be a(n) Double points

15. What is unbalanced force?

16. What is the difference between speed and velocity?

17. What are Velocity has direction, and speed does not.

18. Give a simple example of something that best represents force

19. a push or a pull acting on an object - examples ….

20. When a teacher tries pushing a large desk slowly across the classroom floor, but the large desk will not move, what is keeping the desk from moving?

21. What is static friction ?

22. speed of an object in a particular direction

23. What is velocity ?

24. A force that opposes motion between two surfaces is ____________________?

25. What is friction

26. What can cause a change in speed, direction, or both?

27. What is unbalanced forces ?

28. What is a force that opposes motion between two surfaces that are in contact?

29. What is friction

30. When a clock with moving hands is running, are the hands of the clock accelerating? Explain

31. Yes, they are accelerating, because they are constantly changing direction, even though their speed is the same all the time.

32. What are the two factors that determine the amount of friction?

33. What are: the force and the roughness of the surfaces

34. A hiker’s initial speed at the bottom of the hill is 1.8 m/s and 1.5 m/s when the hiker reaches the top. It took the hiker 180 s to climb the hill. Explain how to calculate the hiker’s acceleration, including whether it would be positive or negative. Double points

35. Subtract 1.8 m/s from 1.5 m/s. 1.5 – 1.8 = - .3 Divide that by the 180 seconds that it took the hiker to get to the top of the hill. -.3 / 180 = - .00166 m/s/s up We know the answer will be negative, because the final speed is slower than the initial speed.

36. Give an example that illustrates an object being opposed by static friction?

37. What is a worker pushing on a non-moving box?

38. Give an example of an something where friction is helpful? & Give an example of an activity where friction is harmful?

39. What are + car tires moving a car forward +Brakes stopping a car -car engine parts wearing out -Wallet wearing out a pocket in pants

40. What distinguishes the measurement of speed from that of velocity and acceleration? Double points

41. Speed does not involve direction. Both velocity and acceleration do include direction.?

42. Friction occurs because of

43. A the roughness of any object’s surface

44. Two forces act on an object. One force has a magnitude of 20 N and is directed toward the north. The other has a magnitude of 15 N directed toward the south. The object experiences a net force of….

45. What is 5 N north?

46. Forces on an object are combined to determine the ____________________ on that object.

47. What is net force?

48. The newton is the SI unit of ____________________.

49. What is force?

50. A force that always acts to oppose motion is ____________________.