1. Chapter 7 Review Mr. Hauser

2. Rules of the Game Working in TEAMS, you will be asked to answer questions from the assigned chapters. You have 30 seconds to write the answer down on the dry erase board. When the teacher says TIME’S UP, a team leader will stand up and show the teacher their answer.

3. Rules (Continued) Each correct answer is worth one point, unless otherwise stated. Teams can lose points for inappropriate conduct, comments, or cheating. The team with the most points at the end of the game wins!

4. Question 1 A projectile that is shot fast enough so that its curved path of falling matches the curvature of the Earth is called …

5. Satellite

6. Question 2 What is the name of the actual shape the orbiting planets follow around the sun?

7. Ellipse

8. Question 3 If an object is undergoing circular motion it is constantly changing its _________. This means it is constantly changing its ___________. This means it must be constantly ____________.

9. Direction, velocity, accelerating

10. Question 4 What is the name of the force that causes circular motion? And, where on the path does it always point?

11. Centripetal force, to the center of the circle

12. Question 5 When the Earth is closer to the sun in its elliptical orbit, it’s moving… A)Faster B)Slower C) The same speed it always does

13. A) Faster

14. Question 6 Since Mars is further away from the sun than Earth, Mars must be moving … A)Faster than Earth. B)Slower than Earth. C)The same speed as Earth.

15. B) Slower than Earth

16. Question 7 A car travels around a 250 m radius race track in a time of 27 seconds. What is the car’s tangential speed?

17. 58.2 meters/second

18. Question 8 How fast must a satellite move in order to orbit Earth? A. 9.8 m/s B. 10 m/s C. 8000 mph D. 8 m/s E. 8000 m/s

19. E) 8,000 m/s

20. Question 9 If the earth’s mass were to suddenly double and your mass were to suddenly double as well, you would weigh _______ your original weight.

21. Four times

22. Question 10 Kepler’s ______ Law says that in their elliptical orbits, planets sweep out equal areas in equal times.

23. Second

24. Question 11 If you quadruple your distance away from the center of the earth you will weigh ______ as much as your original weight.

25. 1/16

26. Question 12 Newton discovered that gravity is _________. A)restricted to planets B)a curvature of space-time C)a contact force D)universal E)varying directly with the distance between objects

27. D) Universal

28. Question 13 A roller coaster has a loop that is 13 meters radius. Find the average centripetal acceleration if it takes 5.2 seconds to make it around the loop.

29. 19 m/s 2

30. Question 14 A ride at an amusement park exerts a centripetal acceleration of 3G’s (This means three times the normal acceleration due to gravity). The tangential speed of the riders is 13.7m/s. What is the radius of the ride?

31. 6.38 meters

32. Question 15 A car has a coefficient of friction 0.93 on a wet road. At what maximum speed can it round a turn of radius 30m?

33. 16.5 m/s

34. Question 16 Two 10 kg steel masses exert a gravitational force on each other of 1.26x10 -7 N. How far apart are they?

35. 0.23 meters

36. Question 17 The “imaginary” force that people describe pulling them to the side of a vehicle while going around a turn is called…

37. Centrifugal force

38. Question 18 The radius of the earth is 6,380,000 meters. Find the tangential speed of someone standing at the equator in meters per second.

39. 464 meters per second

40. Question 19 Black holes are formed by ________ collapsing upon themselves and warping space-time.

41. Stars

42. FINAL QUESTION The earth is a satellite of the sun. It is about 1.5x10 11 m away. How fast is the earth moving in meters per second. Hint: Approximate Earth’s path to a circle.

43. 29,900 meters per second