Jeopardy!

1. Jeopardy!

2. A football starts on the 15-yard line and is carried to the 25-yard line. What position is the origin?

3. 0

4. A footbal player runs from the 30-yard line to the 45-yard line and then back to the 15-yard line. What is his displacement?

5. -15 yards

6. A car is moving in reverse (to the left) and the brakes are being applied to slow it down. What is the direction of the car’s acceleration?

7. Right.

8. State all of the different ways that an object can accelerate.

9. Speed-up, slow-down, change direction.

10. A car is moving at 20 m/s and slows down to 12 m/s with an acceleration of magnitude 2 m/s2. How far does the car move while doing so?

11. 14 meters

12. A basketball and a bowling ball are dropped from the roof of a buidling. Ignoring air drag, which will hit the ground first?

13. Neither -- they both hit at the same time.

14. A car going 20 m/s drives off the end of a flat cliff at the exact same time that a stone falls from rest from the same cliff. Which object hits the ground first?

15. Neither -- they both hit the ground at the same time.

16. A snowmobile moving forward at a constant 20 m/s shoots a flare vertically upward in the sky. Ignoring air drag, where will the flare land, behind, in front of, or back inside the snowmobile?

17. Back inside

18. A basketball is thrown up into the air and returns back to the ground. What is the magnitude and direction of its acceleration at the highest point of its trip?

19. -9.8 m/s2

20. Calculate the maximum height of a ball thrown into the air with an initial velocity of + 20m/s.

21. 20 meters.

22. Which of the following requires a net force?(A) a ball rolling down a hill(B) a hockey puck sliding to a stop(C) a race car driving in a circle at a constant speed

23. All of them.

24. A train runs into a bicycle. Which experiences a greater force -- the bicycle or the train?

25. They each experience the same force.

26. Correct the following statement: my dog weighs 20 kg.

27. My dog has a mass of 20 kg.

28. An object sits at rest on a surface where friction cannot be ignored. Explain how much force is required to get the object moving. Be specific.

29. The applied force must be greater than the maximum force of static friction.

30. A person is moving a box of mass 20 kg by applying a force of 80 N. The force of kinetic friction is 20 N. Calculate the acceleration of the box.

31. 3 m/s2

32. “Fancy” word for the direction of the force and acceleration in circular motion.

33. centripetal

34. What is the direction of the velocity of the tip of the second hand on a clock when it is at the 6 o’clock position?(left, right, up, down?)

35. left

36. A toy airplane is being whirled in a circle at the end of a string. If the string breaks, the plane will fly off in what direction?

37. tangent

38. Calculate the acceleration of a passenger on a roller coaster moving at 20 m/s and turning a corner of radius 10 meters.

39. 40 m/s2

40. If the Earth were to somehow move twice as far from the Sun the force of gravity on the Earth by the Sun would be how many times greater or smaller (state which)?

41. 4 times smaller

42. What is the scientific word for the ability to do work?

43. energy

44. Calculate the work done by a weightlifter who lifts 800 N to a height of 2 meters.

45. 1600 J

46. A woman carries 20 kg of water in a jar on her head for a distance of 2000 meters across a level road. Calculate the work done by her on the jar of water.

47. 0 J

48. Calculate the gravitational potential energy of a 10-kg rock at a height of 20 meters.

49. 2000 J

50. DAILY DOUBLE