Unit 2 mid term review Modified True/False Indicate whether the sentence or statement is true or false. If false, change the identified word or phrase to make the sentence or statement true. 1. Motion is measured relative to a reference point. _ 2. A person standing on a moving escalator is moving relative to another person standing on the escalator. _ 3. A cyclist travels 20 km in half an hour. Her average speed is 10 km/h. _ 4. If one toy car is traveling at 10 cm/s and another toy car is moving at 10 cm/s in the opposite direction, both cars have the same velocity. _ 5. A straight line on a motion graph indicates constant speed. _ 6. A slanted line on a motion graph means that the object is at rest. _ 7. The upper layer of Earth is broken into more than a dozen continents that move very slowly in various directions. _ 8. A child riding on a merry-go-round is accelerating because his direction is changing. _ 9. The SI unit of velocity is the meter per second per second. _ 10. A straight line on a graph of speed versus time means that the object has a constant acceleration. _ Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 11. When an object s distance from another object is changing, a. it is in motion. b. it is speeding. c. it has a high velocity. d. it is accelerating. 12. As Earth orbits the sun, it is moving about a. 30 kilometers per hour. b. 300 kilometers per second. c. 3 kilometers per minute. d. 30 kilometers per second. 13. A place or object used for comparison to determine if something is in motion is called a. a position. b. a reference point. c. a constant. d. velocity. 14. Liters, meters, and grams are all a. distances. b. reference points.
c. units. d. velocities. 15. The basic SI unit of length is the a. meter. b. foot. c. inch. d. mile. 16. The International System of Units is used a. only in the United States. b. only in France. c. in most of Europe. d. all over the world. 17. If you know the distance an object has traveled in a certain amount of time, you can determine a. the size of the object. b. the speed of the object. c. the location of the object. d. the velocity of the object. 18. Speed equals distance divided by a. time. b. velocity. c. size. d. motion. 19. If the speed of an object does NOT change, the object is traveling at a(n) a. constant speed. b. average speed. c. increasing speed. d. decreasing speed. 20. If a bicyclist travels 30 kilometers in two hours, her average speed is a. 30 km/h. b. 60 km/h. c. 15 km/h. d. 2 km/h. 21. If an object moves in the same direction and at a constant speed for 4 hours, which of the following is true? a. The object s speed changed during the 4 hours. b. The object s velocity did not change. c. The object accelerated during the 4 hours. d. The object decelerated during the 4 hours. 22. If you know a car traveled 300 kilometers in 3 hours, you can find its a. acceleration. b. direction. c. average speed. d. velocity. 23. A train that travels 100 kilometers in 4 hours is traveling at what average speed? a. 50 km/h b. 100 km/h c. 2 km/h d. 25 km/h 24. When you know both the speed and the direction of an object s motion, you know the
a. average speed of the object. b. acceleration of the object. c. distance the object has traveled. d. velocity of the object. 25. You can show the motion of an object on a line graph in which you plot distance against a. velocity. b. time. c. speed. d. direction. 26. In graphing motion, the steepness of the slope depends on a. how quickly or slowly the object is moving. b. how far the object has moved. c. when the object began moving. d. the direction the object is moving. 27. On a graph showing distance versus time, a horizontal line represents an object that is a. moving at a constant speed. b. increasing its speed. c. decreasing its speed. d. not moving at all. 28. The upper layer of Earth consists of more than a dozen major pieces called a. units. b. plates. c. continents. d. tectonics. 29. According to the theory of plate tectonics, a. Earth s crust is made of molten lava. b. Earth s plates move ever so slowly. c. Earth s surface has not changed over time. d. Earth s plates move at the same speed as Earth rotates on its axis. 30. Scientists believe that Earth s continents were connected as recently as a. 250 years ago. b. 25,000 years ago. c. 250 million years ago. d. 25 years ago. 31. If one of Earth s plates moves 5 centimeters every year, how far will it move in 500 years? a. 25 kilometers b. 25 centimeters c. 25 meters d. 250 kilometers 32. In a conversion factor, what is special about the fraction used? a. The denominator is always 1. b. The numerator is always 1. c. The denominator and numerator are equal. d. The denominator is always zero. 33. It is rare for any motion to a. stay the same for very long. b. change quickly. c. increase in velocity. d. decrease in speed.
34. The rate at which velocity changes is called a. speed. b. direction. c. acceleration. d. motion. 35. Changing direction is an example of a kind of a. acceleration. b. speed. c. velocity. d. constant rate. 36. Which of these is an example of deceleration? a. a bird taking off for flight b. a baseball released by a pitcher c. a car approaching a red light d. an airplane following a straight flight path 37. The moon accelerates because it is a. in a vacuum in space. b. continuously changing direction. c. a very large sphere. d. constantly increasing its speed of orbit. 38. To determine the acceleration rate of an object, you must calculate the change in velocity during each unit of a. speed. b. time. c. motion. d. deceleration. 39. If velocity is measured in kilometers per hour and time is measured in hours, the unit of acceleration is a. hours. b. kilometers per hour. c. kilometers per hour per hour. d. kilometers. 40. In an acceleration graph showing speed versus time, a straight line shows the acceleration is a. decreasing. b. increasing. c. changing. d. constant. Completion Complete each sentence or statement. 41. A reference point is assumed to be, or not moving. 42. A change in an object s position relative to a reference point is called. 43. When riding a bicycle past a building, you are not moving relative to the.
44. Suppose you are sitting in a car at a red light when a car moving toward the north begins to pass you. If you use the passing car as a reference point, the direction in which you appear to be moving is toward the. 45. The distance traveled by a moving object per unit of time is called. 46. The basic SI unit of length is the. 47. Speed that does not change is referred to as speed. 48. The statement that the motion of a hurricane is 20 kilometers per hour in an easterly direction is a description of the hurricane s. 49. A speed of 15 kilometers per hour is abbreviated as 15. 50. If two lines appear on the same motion graph, the line with the steeper indicates a greater speed. 51. According to the theory of plate, Earth s plates move very slowly in various directions. 52. The boundaries between the plates that make up the upper layer of Earth are cracks in Earth s. 53. Acceleration is the rate of change in. 54. _ occurs when an object slows down. 55. A golf ball when either its speed or its direction changes. 56. The motion of a car stopping at a traffic light is an example of acceleration, also called deceleration. 57. The abbreviation of the unit of acceleration (meters per second per second) is. 58. If a ship has an acceleration of 3 kilometers per hour per hour, its speed is expressed in the unit. 59. If a car is speeding up, its initial speed is than its final speed. 60. If a train traveling north at 30 m/s brakes to a stop in 1 minute, its acceleration is southward.
Unit 2 mid term review Answer Section MODIFIED TRUE/FALSE 1. T 2. F, stationary 3. F, 40 km/h 4. F, speed 5. T 6. F, horizontal 7. F, plates 8. T 9. F, acceleration 10. T MULTIPLE CHOICE 11. A 12. D 13. B 14. C 15. A 16. D 17. B 18. A 19. A 20. C 21. B 22. C 23. D 24. D 25. B 26. A 27. D 28. B 29. B 30. C 31. C 32. C 33. A 34. C 35. A 36. C 37. B 38. B
39. C 40. D COMPLETION 41. stationary 42. motion 43. bicycle 44. south 45. speed 46. meter 47. constant 48. velocity 49. km/h 50. slope 51. tectonics 52. crust 53. velocity 54. Deceleration 55. accelerates 56. negative 57. m/s 2 58. km/h 59. lower 60. 0.5 m/s 2