Semester Exam Eigth Grade SG

Transcription

1 Semester Exam Eigth Grade SG Multiple Choice Identify the letter of the choice that best completes the statement or answers the question m is equal to a. 100 cm. c. 10,000 mm. b. 1,000 cm. d. Both (b) and (c) 2. The statement "Sheila has a stain on her shirt" is an example of a(n) a. law. c. observation. b. hypothesis. d. prediction. 3. How many milliliters are in 3.5 kl? a. 3,500 ml c. 3,500,000 ml b ml d. 35,000 ml 4. Physical science is often divided into physics and a. biology. c. astronomy. b. chemistry. d. geology. 5. The length of a pencil is best measured in a. centiliters. c. meters. b. centimeters. d. kilograms. 6. can help scientists to predict an observation that they might make in the future. a. Data c. Energy b. Theories d. Matter 7. After forming a hypothesis, you should a. test your hypothesis. c. analyze the results. b. ask a question. d. draw conclusions. 8. A prototype, or, of a new car can show investors the features a car company would like to include in their latest design. a. technology c. model b. tool d. prediction 9. An appropriate SI unit for density would be a. g. c. g/cm 3. b. L/m 3. d. m. 10. Air does NOT have a. volume. c. density. b. mass. d. length. 11. The measure of how much surface an object has is its a. length. c. density. b. volume. d. area. 12. The International System of Units a. is based on standardized body measurements. b. contains units that are based on the number 10. c. is also known as the English system. d. was invented in China. 13. When finding the correct answer to a question or problem, scientists may use a. the steps of the scientific method. c. dense matter from the sun. b. the steps to the Lincoln Memorial. d. particles that travel faster than light. 14. What does the prefix milli- mean?

2 a. 1/1,000 c. 100 b. 1/100 d. 1, The SI unit for temperature is a. milliliters (ml). c. degrees Fahrenheit ( F). b. kelvins (K). d. grams per cubic centimeter (g/cm 3 ). 16. When you add a rock to 70 ml of water in a graduated cylinder, the water rises to 80 ml. The mass of the rock is 20 g. What is the rock's density? a g/cm 3 c. 2 g/cm 3 b. 0.5 g/cm 3 d. 3.5 g/cm The mass of an elephant on the moon would be a. less than its mass on Mars. c. the same as its weight on the moon. b. more than its mass on Mars. d. None of the above 18. Which of the following is NOT a chemical property? a. reactivity with oxygen c. flammability b. malleability d. reactivity with acid 19. Your weight could be expressed in which of the following units? a. pounds c. kilograms b. newtons d. Both (a) and (b) 20. Which of the following is NOT a physical property of matter? a. ductility c. thermal conductivity b. color d. reactivity to water 21. The amount of space taken up by an object is known as the object's a. mass. c. inertia. b. weight. d. volume. 22. Gravity affects an object's a. weight. c. volume. b. mass. d. density. 23. You have 20 ml of liquid mercury. Liquid mercury has a density of g/cm 3. What is the mass of the mercury sample? a g c. 271 g b g d g 24. Considering that gold is one of the densest substances on Earth, which would you rather carry around school in your backpack all day, a kilogram of gold or a kilogram of feathers? a. feathers, because your backpack would feel lighter b. gold, because your backpack would feel lighter c. gold, because it would take up less space in your backpack d. feathers, because they would take up less space in your backpack 25. Color, odor, mass, and volume are of an object. a. chemical properties c. stationary properties b. physical properties d. inertial properties 26. A sponge and brick that are the same size have the same a. mass. c. weight. b. volume. d. density. 27. If all of your schoolbooks combined have a mass of 3 kg, their total weight would be about a. 3,000 g. c. 3,000 N. b. 3 kg. d. 30 N. 28. A lead ball has a mass of 454 g. The density of lead is g/cm 3. What is the ball's volume? a cm 3 c cm 3

3 b. 40 cm 3 d. 5,152.9 cm Making aluminum foil demonstrates a. a chemical property. c. ductility. b. malleability. d. conductivity. 30. A book has a length of 25 cm, a width of 20 cm, and a height of 5 cm. What is its volume? a. 50 cm c. 2,500 cm 3 b. 50 cm 3 d. 2,500 cm 31. Which of the following has the LEAST matter? a. an elephant c. a golf ball b. a bowling ball d. a table tennis ball 32. Which of the following describes what happens as the temperature of a gas in a balloon increases? a. The speed of the particles decreases. b. The volume of the gas increases and the speed of the particles increases. c. The volume decreases. d. The pressure decreases. 33. Boyle s law explains the relationship between volume and pressure for a fixed amount of a a. solid. c. gas. b. liquid. d. plasma. 34. The four most familiar states of matter are a. solid, liquid, gas, and sublimation. b. melting, freezing, vaporization, and condensation. c. solid, liquid, gas, and plasma. d. crystalline, amorphous, endothermic, and exothermic. 35. The amount of force exerted on a given area is called a. pressure. c. energy. b. viscosity. d. temperature. 36. do NOT change shape in different containers. a. Solids c. Gases b. Liquids d. Plasmas 37. You can cause water to change state by removing or adding a. matter. c. energy. b. particles. d. surface tension. 38. Freezing and occur at the same temperature. a. melting c. condensation b. vaporization d. sublimation 39. Which of the following does NOT describe pressure? a. the amount of force exerted on a given area b. decreases as particles move faster c. caused by collisions of particles against the inside of a container d. increases as more particles are placed in a container 40. When a substance loses or absorbs energy, a. its temperature can change. c. the speed of its particles can change. b. its state can change. d. All of the above 41. If energy is removed from water that is at 1ºC, the water will a. warm up. c. cool down. b. melt. d. freeze. 42. Water redeposits into lakes in the form of rain by a. sublimation. c. condensation.

4 b. vaporization. d. boiling. 43. Friction is a force that a. opposes an object s motion. b. does not exist when surfaces are very smooth. c. decreases with larger mass. d. All of the above 44. A force a. is expressed in newtons. b. can cause an object to speed up, slow down, or change direction. c. is a push or a pull. d. All of the above 45. The SI unit for speed is a. km/h. c. m/s. b. f/s. d. m/h. 46. Acceleration is a change in a. speed. c. direction. b. velocity. d. All of the above 47. A cheetah runs eastward at a velocity of 27 m/s. Two seconds later, it tackles its prey to the ground. What is the cheetah's acceleration? a. 27 m/s eastward c m/s eastward b. 27 m/s/s eastward d m/s/s eastward 48. When velocity decreases, this could be referred to as a. acceleration. c. negative acceleration. b. deceleration. d. All of the above 49. A force that opposes motion between two surfaces that are touching is a. gravity. c. velocity. b. friction. d. acceleration. 50. After several thousand kilometers, the treads on a car's tires wear away, making them very smooth. Which type of friction is mainly responsible for this? a. sliding c. fluid b. rolling d. static 51. Mass is measured with a a. hydrometer. c. newtonmeter. b. balance. d. barometer. 52. The air that comes out of the tiny holes of an air-hockey table is an example of a. net force. c. gas lubricant. b. friction. d. liquid lubricant. 53. You are in-line skating on a path. As you skate up a slight hill, you slow down. This illustrates a. acceleration. c. deceleration. b. negative acceleration. d. All of the above 54. One Saturday, you go on a picnic. Although there is a slight breeze, the napkins stay on the tablecloth because of a. sliding friction. c. fluid friction. b. rolling friction. d. static friction. 55. When a soccer ball is kicked, the action and reaction forces do NOT cancel each other out because a. the force of the foot on the ball is bigger than the force of the ball on the foot. b. the forces act on two different objects. c. the forces act at different times.

5 d. All of the above 56. A golf ball and a bowling ball are moving at the same velocity. Which has more momentum? a. the golf ball, because it has less mass b. the bowling ball, because it has more mass c. They both have the same momentum because they have the same velocity. d. There is no way to know without additional information. 57. Astronauts float inside the space shuttle because they a. are massless. b. have no gravitational force acting on them. c. are in free fall. d. are weightless. 58. An example of an object in projectile motion is a. a leaping frog. c. riding a bicycle. b. a game of billiards. d. pushing a shopping cart. 59. Newton's third law of motion states that if a force is exerted on an object, another force occurs that a. is equal in size and opposite in direction. b. is in the same direction and size. c. is equal in speed and opposite in direction. d. is in the same direction and speed. 60. After a motor pulls the roller coaster cars up the first hill, what keeps the cars moving up and over the following hills, turns, and loops? a. gravity c. acceleration b. inertia d. all of the above 61. The unit for work is the a. joule. c. newton. b. joule per second. d. watt. 62. Power is a. how strong someone or something is. c. how much work is being done. b. how much force is being used. d. how fast work is being done. 63. The unit for power is the a. newton. c. watt. b. kilogram. d. joule. 64. Levers are divided into classes according to the location of a. the fulcrum. b. the load. c. the input force. d. the fulcrum, the load, and the input force. 65. If you do 50 J of work in 5 s, your power is a. 10 W. c. 55 W. b. 45 W. d. 250 W. 66. Which of the following is NOT an example of doing work on a suitcase? a. carrying a heavy suitcase down a long hallway b. lifting a heavy suitcase up and putting it on a top shelf c. pulling a wheeled suitcase down a long corridor d. sliding a heavy suitcase across a bed to move it out of the way 67. In a second-class lever, a. the load is between the fulcrum and the input force. b. the fulcrum is between the input force and the load. c. the input force is between the fulcrum and the load.

6 d. the fulcrum is between the input force and the output force. 68. Hammering a nail into wood is an example of using a a. wedge. c. second-class lever. b. first-class lever d. third-class lever. 69. A movable pulley a. is attached to the load. c. has a mechanical advantage of 1. b. works by pulling down on the rope. d. has the same output force as input force. 70. Our most important energy resource is/are a. the sun. c. fossil fuels. b. plants. d. wind.

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