Conceptual Physics Study Guide for the 3^rd Six Weeks Test

1. What makes a hypothesis a scientifically valid hypothesis?

2. Scientific theories constantly change. Is this a strength or a weakness?

3. Religion is about cosmic ___; while science is about cosmic ___.

4. What makes a scientific theory a good scientific theory?

5. When an object falls through a vacuum on Earth which changes: the object’s acceleration or the object’s velocity?

6. Consider an object falling through the air: What happens to the object’s acceleration?

7. Consider an object falling through the air: What happens to its velocity?

8. Consider an object falling through the air: What happens to the distance the object covers each second?

9. How is it possible to accelerate without changing speed?

10. What are three ways of changing velocity?

11. How many forces are acting on an object in free fall?

12. What is the direction of the force acting on an object in free fall?

13. How must these vectors be re-drawn so that a resultant can be found?

14. What effect, if any, does the horizontal motion of a projectile have on the vertical motion?

15. If an object is thrown horizontally while at the same time another object is dropped from the same height, which object, if either, will hit the ground first?

16. Why are object in orbit considered projectiles?

17. How many forces are acting on an object in orbit; what is the name of that force?

18. What is the vertical acceleration of an object that is thrown horizontally?

19. What is the horizontal acceleration of a projectile?

20. If you throw an object into the air it becomes a projectile; in which direction is the motion at constant velocity; in which direction does the object accelerate at 9.8 m/s²?

21. Consider a 24 kg mass on Earth, what will its mass be if the object Is taken to the moon where the force of gravity is 1/6 that of Earth?

22. Mr. Young and a student have a race to the lunch room. At the end of the hall Mr. Young has a more difficult time turning than the student. Why?

23. If the race described in #22 were to occur on the moon would Mr. Young have an easier time making the turn at the end of the hall? Remember that on the moon even Mr. Young weighs 6 times less than he does on Earth.

24. Consider object ‘A’ that weighs 10 N on Earth and another object. Object ‘B’ that weighs 10 N on the moon. Which object has the greatest mass?

25. What is the magnitude of the net force of an object in equilibrium?

26. Negating friction, how much force is needed to keep an object moving at a constant velocity?

27. What is the weight of objects in free fall?

28. As an object fall through the air its velocity ___ while at the same time its acceleration ___.

29. How does one calculate the net force acting on an object?

30. What is the net force acting on the object pictured below?

31. Why do all objects that fall near Earth’s surface accelerate at 9.8 m/s²?

32. According to Newton’s third law why is it impossible to hit a hanging sheet of paper with a very large force?

33. According to Newton’s third law if you hit a wall with a force of 1000 N how hard will the wall hit back?

34. How is it possible for a rocket to accelerate in the vacuum of space?

35. A 0.003 kg bullet is fired at 360 m/s. What is its momentum?

36. A force is necessary for a car to accelerate down the road. What actually acts on the car so that it can accelerate?

37. One team in a tug-o-war pulls on the rope with a force of 5000N. How much force must the other team exert?

38. Can one team in a tug-o-war ever apply less force than the other team?

39. How does one team win in a tug-o-war?

40. Two teams pull on a rope in a tug-o-war with a force of 5000 N. What is the net force on the rope?

41. When a student jumps from a table to the floor they always bend their knees; what does this action do to the time it takes for the student to come to a stop?

42. When a student jumps from a table to the floor they always bend their knees; what does this action do to the force needed for the student to come to a stop?

43. Upon what two quantities does kinetic energy depend?

44. A 55 kg student is riding on his skate board with a momentum of 242 kgm/s. What is his velocity?

45. A basketball with a mass of 0.62 kg is thrown so that it has a velocity of 5.0 m/s. What is its momentum?

46. Write the equation used to calculate kinetic energy.

47. What does power measure?

48. Write the equation used to calculate power.

49. What is the SI unit for work?

50. What is the SI unit for power?

51. What is the SI u nit for energy?

52. A force of 150 N is needed to lift a box 3.5 m. How much work was done?

53. Compare the speed of a satellite orbiting Earth in elliptical orbit when the satellite is closest to Earth to when the satellite is farthest from Earth. At which point is it moving fastest, at which point is it moving slowest?

54. What is the source of energy to run a car?

55. Ultimately, what is the source of energy to run the radio in the car?

56. Ultimately, what is the source of energy to run the headlight of a car?

57. How did Newton know that there must be an unbalanced force acting on the moon?

58. The moon falls 1.4 mm every second; why does the moon not fall to Earth?

59. If the force of gravity between two massive objects is 50 N; what will that force be if the distance between them is increased to five times what it was?

60. Write the equation used to calculate the force of gravity between any two objects in the universe.

61. What, exactly, did Newton discover about gravity?

62. What is heat?

63. How is it possible for a substance to gain or lose energy without changing its temperature?

64. At what temperature must a lake be before it can begin freezing?

65. At what temperature is water at its most dense?

66. What is internal energy?

67. What is temperature?

68. What is the difference between a calorie and a Calorie?

69. Why does the desk leg feel cold while the blankets in Mr. Young’s room feel warm yet both are at the same temperature?

70. Why does a bimetallic strip bend when heated or cooled?

71. A cup of hot coco sits on a counter and cools; when will it stop cooling?

72. What kind of an emitter is a good absorber of energy?

73. What absorbs energy better: a black coffee cup or a white coffee cup?

74. In which coffee cup will coffee cool fastest: A white cup or a black cup?

75. Note the figure:

If the ring is put over a flame what will happen?

76. What temperature must a lake reach before the lake can freeze?

77. Does a blanket make you warm or just keep you warm?

78. Which blanket will keep you warmer: A thick heavy wool blanket or a thick lilghtweight down quilt?

79. What is the name given to the process of energy being transferred from one place where it is hot to where it is cold?

80. Note the figure below. Which term best describes how the marshmallows are getting hot?

81. According to Newton’s Law of Cooling which will cool fastest: A can of room temperature coke in the refrigerator or a can room temperature coke in the freezer?

82. State Newton’s Law of Cooling.

83. According to Newton’s Law of Cooling which is it better to do: Turn the heat in your house down while you are gone to school, or to turn the heat completely off?

84. What does the specific heat of a substance tell you?

85. What substance has the highest specific heat?

86. Which substance requires more energy to change its temperature: A substance with a high specific heat or a substance with a low specific heat?

87. Note the illustration below:

This is an example of energy being transferred by ___?

88. Note the cartoon below. What kind of energy transfer is warming the hands, feet and hooves of the characters in the cartoon?

89. How does the sun transfer its energy through the 93 million miles of vacuous space to Earth?

90. What kind of energy transfer involves electromagnetic waves?

91. What actually conducts energy in a metal rod held to a fire?

92. What does an insulator do to the transfer of energy?

93. What does a conductor do to the transfer of energy?

94. Note the figure below. By what means is energy transferred from the flame to the hand?

95. As warm air rises what happens to it?

96. A cold air descends what happens to it?

97. What is the name given to the electromagnetic waves that transfer energy from a fire to your hands held before it?

98. Note the white box in Mr. Young’s room with the black hole in front. Why is the hole black?

99. The sun gives off short wavelength radiation; what kind of radiation does Earth emit?

100. What is the greenhouse effect?