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Transcript
HONORS PHYSICS PRACTICE FINAL In no way does this represent the actual questions on the final. It should serve as a way for you to identify your weakness and strengths and give you direction for your studies. Questions that are crossed out do not relate to content on your final….skip them. Modified True/False Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true. ____ 1. As the speed of a ball rolling on the floor decreases, its potential energy decreases. _________________________ ____ 2. The rate of doing work is called energy. _________________________ ____ 3. In many circuit diagrams, any electrical device that uses energy is shown with a resistor symbol. _________________________ ____ 4. A closed circuit has a break in it. _________________________ ____ 5. Electric current is the difference in energy per unit of charge between two points in a circuit. _________________________ ____ 6. An ohm is the unit of measurement for current. _________________________ ____ 7. Electric current will flow easily through a conductor. _________________________ ____ 8. A series circuit contains branching points and multiple paths for current to flow through. _________________________ ____ 9. Each branch of a parallel circuit has the same voltage. _________________________ ____ 10. The coulomb is the unit of measure for charge. _________________________ ____ 11. The electric force between two charged objects increases as the distance between them increases. _________________________ ____ 12. Because of Ben Franklin’s work, current is always defined as going from negative to positive. _________________________ ____ 13. Some of the electrons in insulators are free to move throughout the material. _________________________ ____ 14. A sound wave is an example of a longitudinal wave. _________________________ Multiple Choice Identify the choice that best completes the statement or answers the question. ____ 15. As the speed of a rolling ball is increasing, the increasing speed is accompanied by: a. increasing momentum. c. decreasing momentum. b. increasing inertia. d. both increasing inertia and momentum. LORI DUNN ____ 16. Even though every action force has an equal but opposite reaction force, they do not cancel one another and motion may still occur because the: a. action and reaction forces are applied to the same object. b. action and reaction forces are applied to different objects. c. two forces have different magnitudes. d. two forces have equal magnitudes. ____ 17. To calculate momentum: a. add the mass of an object to its inertia. b. add the mass of an object to its velocity. c. multiply the mass of an object by its inertia d. multiply the mass of an object by its velocity. ____ 18. The impulse applied to an object is equal to the change in the object’s: a. mass. c. momentum. b. inertia. d. height. ____ 19. To increase the final momentum of a racquetball, the player should: a. swing the racquet as fast as possible. c. increase contact time with the ball. b. follow through when hitting the ball. d. All of the above ____ 20. The impulse necessary to change the momentum of a 20-kilogram object by 5 kg·m/sec is: a. 4 kg·m/sec. c. 15 kg·m/sec. b. 5 kg·m/sec. d. 100 kg·m/sec. ____ 21. The momentum of a 2000 kilogram car traveling at 20 meters per second is: a. 0 kg·m/sec. c. 100 kg·m/sec. b. 0.001 kg·m/sec. d. 40,000 kg·m/sec. ____ 22. If a 40,000 kilogram rocket were traveling from its launch pad at a speed of 150 meters per second, 800 kilograms of gases would be expelled from the rocket at a speed of about: a. 0.33 m/sec. c. 7,500 m/sec. b. 270 m/sec. d. 21,000 m/sec. ____ 23. Ken rolls a 7-kilogram bowling ball so slowly that it stops before it moves through all of the pins. The impulse necessary to stop this bowling ball rolling at 2 meters per second is ____ newton-seconds. a. 3.5 c. 7.0 b. 5.0 d. 14 ____ 24. While standing on a stationary skateboard, Jolene tosses a heavy ball horizontally toward one end of her skateboard. The skateboard moves. Assuming there is no friction in the system when the ball is tossed, which statement about the momentum of the heavy ball is INCORRECT? a. The ball’s momentum is equal in size to the momentum of Jolene and her skateboard. b. The ball’s momentum plus the momentum of Jolene and her skateboard equals zero. c. The ball’s momentum has increased because Jolene has tossed it. d. The directions of the ball’s momentum and Jolene’s momentum are the same. LORI DUNN ____ 25. Alex hits a line drive directly up the middle which leaves his bat traveling at 250 meters per second. If the pitcher has thrown the 0.15-kilogram baseball to Alex at 140 meters per second, what is the impulse applied to the baseball by Alex? a. 17 newton-seconds c. 38 newton-seconds b. 21 newton-seconds d. 59 newton-seconds ____ 26. A 0.15-kilogram baseball thrown at a speed of 50 meters per second and a 7.25-kilogram bowling ball rolling at 2 meters per second are both stopped in 0.2 seconds. a. The baseball is stopped with less force because it has less inertia. b. The baseball is stopped with less force because it has less momentum. c. The bowling ball is stopped with less force because it has less momentum. d. The bowling ball is stopped with less force because it has less inertia. ____ 27. What impulse must be applied to a 3-kilogram object to give it 150 joules of kinetic energy? a. 21 newton-seconds c. 50 newton-seconds b. 30 newton-seconds d. 3,000 newton-seconds ____ 28. Jumping on a trampoline, Jeffrey can easily soar 6 feet into the air but can only jump 2 feet from the blacktop of the driveway basketball court because the: a. court applies a larger impulse. b. trampoline applies a larger impulse. c. court applies less force on Jeffrey. d. trampoline applies more force on Jeffrey. ____ 29. Energy that is stored due to the position of an object may be called ____ energy. a. kinetic c. radiant b. potential d. nuclear ____ 30. A 20-kilogram object falls 2.0 meters to the floor. At what point in its fall does the kinetic energy of a body equal its potential energy? a. At all points of the fall c. Halfway to the floor b. Very nearly at the top of the fall d. Just the instant before it hits the floor ____ 31. An object falls without friction near Earth’s surface. The loss of its potential energy is equal to its: a. loss of height. c. gain in kinetic energy. b. loss of mass. d. gain in velocity. ____ 32. The diagram below represents a cart traveling from left to right along a frictionless surface with an initial speed of 3 m/sec. At what point is the potential energy least? a. A LORI DUNN b. B c. C d. D ____ 33. The ability to cause change is defined as: a. force and is measured in newtons. b. power and is measured in watts. c. energy and is measured in joules. d. impulse and is measured in newton-seconds. ____ 34. Work may be measured using units of: a. watts. b. newtons. ____ 35. In science, work is defined as: a. the mass of an object multiplied by its acceleration. b. the mass of an object multiplied by the force required to move it. c. force multiplied by the distance moved in a direction perpendicular to the force. d. force multiplied by the distance moved in the same direction as the force. ____ 36. Potential energy increases as a marble: a. slows rolling up an incline. b. increases speed down an incline. ____ 37. Calculate the work done to lift a barbell weighing 100 newtons a distance of 1.5 meters. a. 0.015 joules c. 66.7 joules b. 15 joules d. 150 joules ____ 38. Jonah is pushing his younger sister, Jessica, on a swing. If Jessica weighs 350 newtons, how much higher above the ground must Jonah push her to increase her potential energy by 525 joules? a. 0.67 meters c. 3.6 meters b. 1.5 meters d. 5.4 meters ____ 39. A basketball player who weighs 600 newtons jumps 0.5 meters vertically off the floor.What is her kinetic energy the instant before hitting the floor? a. 30 joules c. 300 joules b. 60 joules d. 600 joules ____ 40. Lifting a 70-kilogram barbell 2.0 meters above the floor increases its potential energy by about: a. 35 joules. c. 350 joules. b. 140 joules. d. 1,400 joules. ____ 41. The amount of mechanical kinetic energy possessed by a 0.25-kilogram ball rolling at a speed of 2.5 meters per second is ____ joules. a. 0.31 b. 0.63 c. 0.78 d. 1.6 ____ 42. As the speed of a moving object doubles, the amount of mechanical kinetic energy that it possesses: a. increases by two times. c. decreases by two times. b. increases by four times. d. decreases by four times. LORI DUNN c. joules. d. newtons per second. c. rolls at uniform speed on a level table. d. sits motionless on the floor. ____ 43. Jonah is pushing his younger sister, Jessica, on a swing. If Jessica weighs 35 kilograms, how much higher above the ground must Jonah push her to increase her potential energy by 525 joules? a. 0.67 meters b. 1.5 meters c. 3.6 meters d. 5.4 meters ____ 44. What braking force is needed to stop a 1,000-kilogram car moving at 10 m/sec in a time of 1 seconds? a. 1 newton c. 100 newtons b. 10 newtons d. 10,000 newtons ____ 45. A 2-kilogram piece of clay moving at 4 m/sec strikes and sticks to a second 4-kilogram piece of clay moving at 1 m/sec in the opposite direction. Calculate the speed of the combined piece of clay. a. 1 m/sec b. 2 m/sec c. 4 m/sec d. 6 m/sec ____ 46. An automobile jack exerts a force of 4,500 newtons to raise a car 0.25 meters. The amount of work done by the jack is about ____ joules. a. 0.00056 b. 1,100 c. 4,500 d. 18,000 ____ 47. The action that would require no work to be done is: a. holding a 100-pound object over your head. b. pushing a 25-kilogram box of books across the floor. c. pedaling a 100-newton bicycle up a small hill. d. lifting a balloon filled with air from the floor to a desktop. ____ 48. A 2.2-kilogram crate is pulled by a 30-newton force over a distance of 5 meters. The work done by pulling the crate is ____ joules. a. 11 b. 66 c. 150 d. 330 ____ 49. Running up a flight of stairs, Maria generates 450 watts of power. If it takes her 6 seconds to go up the stairs, the amount of work she does in running up the stairs is ____ joules. a. 0.013 b. 75 c. 450 d. 2,700 ____ 50. Jasmine, who weighs 400 newtons, moves up a 5.0-meter climbing wall in 15 seconds. The amount of power generated by Jasmine as she climbs the wall is about ____ watts. a. 130 b. 2,000 c. 6,000 d. 30,000 ____ 51. 60 joules of work are required to lift the 10-newton object 5.0 meters as shown in the diagram: The amount of work done in overcoming friction as the weight is lifted is ____ joules. a. 10 b. 50 c. 60 d. 300 ____ 52. The ____ is one kind of particle that makes up the atom and carries a positive charge. LORI DUNN ____ a. electron b. proton 53. Compared to protons, electrons have: a. much smaller mass and opposite charge. b. about the same mass and opposite charge. c. much larger mass and the same charge. d. much larger mass and opposite charge. c. neutron d. plasma ____ 54. The electric charge of an atom with the same number of protons and electrons is: a. equal to the number of protons multiplied by the charge on one proton. b. equal to the number of electrons multiplied by the charge on one electron. c. equal to the number of protons plus the number of neutrons. d. zero. ____ 55. Protons and neutrons are found grouped together in the: a. electron cloud. c. nucleus. b. charge. d. periodic table. ____ 56. The motion of charges in wires, motors, light bulbs and other devices is best called electric: a. power. c. current. b. voltage. d. conductance. ____ 57. In an electrical circuit, the term current refers to: a. resistance. b. potential difference. ____ 58. A device that uses chemical energy to push current in a circuit is called a: a. battery. c. ammeter. b. voltmeter. d. potentiometer. ____ 59. The energy carried by each unit of moving charge in a circuit is called: a. amperage. c. resistance. b. voltage. d. wattage. ____ 60. Which of the following makes a good analogy for a battery? a. Water pipes c. Water faucet b. Narrow areas in water pipes d. Water tower and pump ____ 61. All of the following are considered conductors EXCEPT: a. iron. c. rubber. b. gold. d. copper. ____ 62. Materials through which current will not easily flow are called: a. conductors. c. insulators. b. semiconductors. d. absorbers. ____ 63. Electric current will pass easily through a(n): a. absorber. b. conductor. c. semiconductor. d. insulator. ____ 64. An ohm is the unit of measurement for: a. electrical power. b. voltage. LORI DUNN c. flowing charges. d. energy loss. c. current. ____ d. resistance. 65. In the circuit below, 3 amps of current passes through the light bulb. The resistance of the light bulb is 3 ohms: What is the voltage of the battery? a. 1 volt b. 1 ohm c. 9 volts d. 9 amps ____ 66. As Jing toasts her morning waffle in the family toaster, 4.0 amps of current flows with a voltage of 120 volts across the toaster. The resistance of the toaster is: a. 30 watts. c. 480 watts. b. 30 ohms. d. 0.033 ohms. ____ 67. A light bulb requires 2 amps to produce light. The resistance of the bulb is 3 ohms. How many batteries do you need if each battery is 1.5 volts? a. 6 b. 4 c. 1.5 d. 5 ____ 68. A 120-volt household circuit has a circuit breaker that opens the circuit if it draws more than 12 amps of current. What is the minimum amount of resistance in the circuit required to keep the circuit breaker from activating? a. 0.1 ohms b. 132 ohms c. 1,440 ohms d. 10 ohms ____ 69. If there is a break at any point in a series circuit, the current will: a. stop everywhere in the circuit. b. leak out of the break point. c. be decreased by one-half. d. continue through remaining unbroken circuit branches. ____ 70. When more devices are added to a series circuit, the total circuit resistance: a. decreases. b. increases. c. stays the same. d. may increase or decrease, depending on the device. ____ 71. Suppose you connect more and more light bulbs in series to a battery. What happens to the brightness of each bulb as you add more bulbs? a. The bulbs grow brighter with each new bulb added. b. The bulbs grow dimmer with each new bulb added. c. There is no change in brightness. LORI DUNN d. The brightness may increase or decrease depending on the type of light bulb. The diagram below pictures three identical light bulbs, each with a resistance of 1 ohm, which are connected by resistance-free wires. A 9-volt battery supplies energy to the circuit. Figure 14-1A ____ 72. What type of circuit is the circuit in Figure 14-1A? a. Series b. Parallel ____ 73. The total resistance for the circuit shown in Figure 14-1A is: a. 1 ohm. b. 1 volt. c. 3 ohms. d. 3 volts. ____ 74. The current for the circuit shown in Figure 14-1A is: a. 3 amps. b. 3 ohms. c. 0.33 amps. d. 1 ohm. ____ 75. The voltage drop across each light bulb in Figure 14-1A is ____ volt(s). a. 3 b. 1 c. 0.33 d. 0 ____ 76. The voltage drop across each resistor in the circuit below is ____ volts. a. 1.5 ____ b. 3 c. Compound c. 2 77. The current in a series circuit: a. decreases to zero as it travels through the circuit. b. is the same at all points in a circuit. c. is greatest in the resistor with the highest resistance. d. is greatest in the resistor with the lowest resistance. LORI DUNN d. Current d. 9 ____ 78. The current in each resistor in the circuit below is ____ ampere(s). a. ____ b. 1 c. 3 d. 9 79. Which of the following is TRUE about voltage in a series circuit? The total of all voltage drops must: a. equal the total current. b. add up to zero. c. add up to the total voltage supplied by the battery. d. never exceed the total circuit resistance. Study the circuit diagrams shown below (all bulbs are identical): Figure 14-2A ____ 80. Which of the circuit diagrams shown in Figure 14-2A is a series circuit? a. I only b. II only c. III only d. I and II only ____ 81. Which of the circuit diagrams shown in Figure 14-2A is a parallel circuit? a. I only b. II only c. III only d. I and II only ____ 82. When a new branch containing a resistor is added to a parallel circuit, the total circuit resistance: a. decreases. b. increases. c. stays the same. d. may increase or decrease, depending on the device. LORI DUNN ____ 83. What is the basic difference between series and parallel circuits? a. Simple series circuits are not used in electrical devices; parallel circuits are used in all electrical devices. b. In a series circuit, there are multiple paths for the flow of charge; in a parallel circuit, there are only two paths. c. A series circuit contains one path for the flow of charge; a parallel circuit contains more than one path. d. A series circuit obeys Ohm’s law; a parallel circuit does not obey Ohm’s law. ____ 84. Which of the following statements best describes the difference between series and parallel circuits? a. Series circuits are battery circuits, and parallel circuits are generator circuits. b. Series circuits have a single path, and parallel circuits have two or more paths. c. Series circuits are used in computers, and parallel circuits are used in homes. d. Series circuits have one switch in them, and parallel circuits have two switches in them. ____ 85. The voltage drop across each resistor in the circuit below is ____ volt(s). a. 0.2 ____ c. 6 86. The current in each resistor in the circuit is ____ ampere(s). a. b. 1 ____ b. 5 c. 3 d. 9 87. The voltage across the 1-ohm resistor pictured below is ____ volt(s). LORI DUNN d. 12 a. b. c. 1 d. 3 ____ 88. A student connects three 1-ohm light bulbs to a 9-volt battery in parallel. The total circuit current is ____ ampere(s). a. 1 b. 3 c. 9 d. 27 ____ 89. Which of the following would create a total resistance of 0.5 ohm? a. Four 2-ohm resistors connected in parallel b. Four 2-ohm resistors connected in series c. Eight 2-ohm resistors connected in parallel d. Two 2-ohm resistors connected in series In the circuit shown below, three identical flashlight bulbs are screwed into sockets and are lighted when the circuit is closed: Figure 14-3A ____ 90. Which bulb draws the least amount of current in Figure 14-3A? a. Bulb A b. Bulb B c. Bulb C d. Bulbs B and C draw an equal amount of current but draw less than bulb A. ____ 91. If you unscrewed bulb A in Figure 14-3A: a. only bulb B would go out. b. only bulb C would go out. c. bulbs B and C would go out. d. bulbs B and C would remain lit. ____ 92. If you unscrewed bulb C in Figure 14-3A: a. only bulb A would go out. b. only bulb B would go out. c. bulbs B and C would go out. d. bulbs B and A would remain lit. ____ 93. Positive electric charges: a. attract both positive charges and negative charges. b. repel both positive charges and negative charges. c. attract positive charges and repel negative charges. d. repel positive charges and attract negative charges. LORI DUNN ____ 94. Electric charge is: a. caused by two fluids, as described by Benjamin Franklin. b. present in metals only. c. a fundamental property of matter that has two types, positive and negative. d. found only in non-living material. LORI DUNN ____ 95. The charge of a proton and the charge of an electron have: a. different amount of charge and opposite sign. b. the same amount of charge and opposite sign. c. different amount of charge and the same sign. d. the same amount of charge and the same sign. ____ 96. The diagram that best represents the charge distribution on a neutral electroscope when a negatively charged rod is held near it is: a. A. b. B. c. C. d. D. ____ 97. A rod and a piece of cloth are rubbed together. If the rod acquires a charge of +1 x 10-6 coulomb, the cloth acquires a charge of: a. 0. c. -1 x 10-6 coulomb. b. +1 x 10-6 coulomb. d. +1 x 10+6 coulombs. ____ 98. An electrically neutral object can be attracted by a positively charged object because: a. like charges repel each other. b. the charges on a neutral object can be redistributed. c. the neutral object becomes charged by friction. d. the net charge in a system varies. ____ 99. Determine the electric force exerted on sphere A. a. 9 x 109 newtons b. 1.3 x 1011 newtons c. 1.4 x 1010 newtons d. 1.6 x 109 newtons ____ 100. As the distance between two positively charged objects increases, the force between them: a. increases. c. cannot be determined. b. decreases. d. remains the same. LORI DUNN ____ 101. If the distance between two charges is reduced by half, the electric force between them: a. decreases by c. increases by 2 times. . d. increases by 4 times. b. decreases by . ____ 102. Two point charges attract each other with a force of 8.0 10-5 newtons. If the distance between the charges is doubled, the force of attraction will become ____ newtons. a. 16 x 10-5 b. 2.0 x 10-5 c. 64 x 10-5 d. 4.0 x 10-5 ____ 103. Suppose you rub an inflated party balloon on a carpet, hold the balloon next to a wall, and discover that it “sticks” to the wall. Why did the balloon stick to the wall? a. The total charge on the balloon and wall becomes zero, so attraction between the two can occur. b. Like charges on the balloon and wall cause an attraction between the two. c. Balloons contain a special “atomic glue” that allows them to cling to other objects. d. Excess charge builds up on the balloon and electrostatic forces allow the balloon and wall to be attracted to one another. ____ 104. Almost all of the electrons flowing through a battery circuit come from atoms: a. in the wire conductor. b. in the circuit components. c. involved in chemical reactions at the battery's negative terminal. d. involved in chemical reactions at the battery's positive terminal. ____ 105. The electrons in an insulator are best described as: a. free to move. c. flowing charges. b. fixed in place. d. a potential difference. ____ 106. Oscillating (but not harmonically) systems include all of the following EXCEPT: a. the moving pedals on a bicycle. b. a radio signal from FM station 106.3. c. Earth turning on its axis. d. a block sliding down a ramp. ____ 107. The measure of the number of cycles per second is called: a. frequency. c. amplitude. b. period. d. vibration. ____ 108. The unit for measuring the frequency of an oscillating system is the: a. meter. c. hertz. b. meter/second. d. hertz/second. ____ 109. The amount of time required for one cycle to occur is called the: a. amplitude. b. frequency. c. harmonic. d. period. ____ 110. A pendulum makes one complete swing over and back in 2.2 seconds. Its frequency is: a. 0.45 hertz. b. 0.45 seconds. c. 2.2 hertz. d. 2.2 second. LORI DUNN ____ 111. The diagram below represents a graph of harmonic motion: One cycle of the motion is represented by the distance from: a. A to B. b. B to D. c. B to E. d. A to E. ____ 112. A graph of harmonic motion shows that a cycle lasts 8.0 seconds. What is the frequency of this oscillator? a. 0.125 hertz b. 0.125 seconds c. 8.0 hertz d. 8.0 seconds ____ 113. The graph below represents position versus time for the amplitude of a pendulum that was allowed to swing for four seconds: Which letter correctly identifies the amplitude of the pendulum? a. A b. B c. C d. D ____ 114. The diagram below represents a segment of a periodic wave: Which two points represent the same point in a cycle? a. C and I b. A and D c. B and E ____ 115. Which of the following is NOT a property of waves? a. Frequency b. Amplitude c. Speed LORI DUNN d. C and H d. Weight ____ 116. The product of the frequency and the length of a wave yields its: a. period. b. amplitude. c. cycle. d. speed. Figure 20-1A The diagram represents a wave pattern in a certain medium. Answer the following questions based on the diagram. ____ 117. Referring to Figure 20-1A, the wavelength in the diagram is represented by the distance from: a. A to D. b. B to C. c. D to F. d. F to G. ____ 118. Referring to Figure 20-1A, the distance from point A to point G is 6.0 meters. If the speed of the wave is 330 meters per second, the frequency of this wave is ____ Hz. a. 55 b. 165 c. 660 d. 1,980 Hz ____ 119. The wavelength of a certain frequency of light is 5 x 10-7 meters. If the speed of light is 300,000 km/sec, the frequency of the light is ____ hertz. a. 1.67 x 10-15 b. 1.67 x 10-12 c. 6.00 x 1011 d. 6.00 x 1014 ____ 120. The bending of a wave front around a barrier is called: a. reflection. b. refraction. c. diffraction. d. absorption. ____ 121. The diagram represents a wave interaction as wave fronts pass through a small opening. This is an example of: a. diffraction. b. refraction. c. reflection. d. absorption. ____ 122. As a wave front crosses a boundary between two different media, the wave front may change direction, an interaction known as: LORI DUNN a. reflection. b. refraction. c. diffraction. d. absorption. ____ 123. Theaters often use heavy curtains to reduce echoes during performances. The function of the curtains is to ____ sound. a. refract b. reflect c. diffract d. absorb ____ 124. The direction a wave moves is: a. parallel to the wave fronts. b. perpendicular to the wave fronts. c. in the direction of increasing amplitude. d. in the direction of decreasing frequency. ____ 125. You are still able to hear sounds coming from a room when the door is open only a tiny crack due to: a. reflection. b. refraction. c. diffraction. d. absorption. ____ 126. Two large waves on the ocean come together on the ocean’s surface to form a gigantic wave. The interaction responsible for this is called: a. frequency amplification. c. destructive interference. b. constructive interference. d. amplitude destruction. ____ 127. Which pair of moving pulses in a rope will produce destructive interference? a. A b. B c. C d. D Completion Complete each statement. 128. As Maria steps from a small rowboat towards a pier, the boat moves away from the pier. Maria falls into the water. She is a “victim” of the law of conservation of ____________________. 129. Alicia is asked to calculate the change in momentum that occurs as she stops her bicycle. This is equivalent to the ____________________ applied to the bicycle. 130. The expression F t represents ____________________. 131. The expression mgh represents ____________________ energy. 132. The kinetic energy of an object depends upon two things: ____________________ and ____________________ . 133. “Energy can never be created or destroyed, just transformed from one form to another” is a statement of the law of ______________________________ (three words). LORI DUNN 134. The expression mv2 represents ____________________ energy. 135. For an object to do work, it must possess ____________________. 136. The work Brandon does in lifting a rock is calculated by multiplying the weight of the rock by the change in the ____________________ of the rock. 137. A complete path through which electricity travels is called a ____________________. 138. A shorthand method of describing a real circuit using electrical symbols is called a ____________________ (two words). 139. A device used to create an intentional break in a circuit to stop the flow of current is a ____________________. 140. Differences in ____________________ cause charge to flow. 141. Each separate resistor in a series circuit creates a(n) ____________________ drop. 142. The total circuit resistance ____________________ as more resistors are added in parallel. 143. The build up of electric charge on an object is called ____________________ electricity. 144. If an object has more negative charges than positive charges, the ____________________ charge is negative. 145. Atoms are ____________________ when one end is positive and one end is negative. 146. Two negative charges will ____________________ each other. 147. An object with equal amounts of positive and negative charge is called __________. 148. When we say current is moving through a circuit, we mean ____________________ (two words) is moving through the circuit. Short Answer 149. A speeding truck makes contact with a bug on its windshield. Compare the force that the bug exerts on the truck to the force the truck exerts on the bug. 150. As a tennis player, golfer, baseball player or soccer player you might be told by your coach to “follow through” when striking the ball. Explain why. 151. A ball is thrown from position (1) to a height of 5 meters above at position (2), giving the ball potential energy. The ball then falls to position (3). Assuming there is no loss of energy due to friction: LORI DUNN A. Name the height at which the kinetic energy of the ball would be exactly the same its potential energy? B. Compare the potential energy at (3) to the kinetic energy at (2). C. Compare the kinetic energy at (1) to the potential energy at (2). 152. On Monday, Bik runs upstairs carrying a heavy book. The next day, she walks upstairs carrying the same book. Compare Bik’s work and power on Monday and Tuesday. 153. Why are circuit diagrams drawn? 154. You install two batteries in a flashlight so that their positive ends are facing each other. Will the flashlight work? Why or why not? 155. The circuit shown below has 3 identical bulbs connected in series to a battery. If 1 bulb is unscrewed, what will happen to the 2 remaining bulbs? 156. Name the two ways that an electrically neutral object can become positively charged. 157. Two positively charged objects are separated from each other by 1 centimeter. What is the direction of the electrical force between them? 158. Name the two factors that determine the strength of the electrical force between two charged objects, and describe how these two factors influence the force between the two objects. LORI DUNN 159. If the distance between charges is reduced by half, what happens to the force between them? 160. What does the term “charging by friction” mean, and what happens to the charge of the objects involved? Give one example. 161. Explain what creates a current in a conductor. 162. How many waves are represented in this diagram? 163. List four things that may happen to a wave as it meets a boundary. Problems 164. Calculate the momentum of a 30-kilogram cart moving at a speed of 2.0 meters per second. 165. While sitting motionless on a 10-kilogram, friction-free wagon, 75-kilogram “Bozo, the human target” catches an 8-kilogram cannonball moving at 15 meters per second. After catching the cannonball, at what speed do Bozo, the wagon and cannonball move? 166. Calculate the size of the impulse that must be applied to stop a 200-kilogram wagon rolling on a flat path at a speed of 4.5 meters per second. 167. Calculate the speed of a 0.25-kilogram water balloon propelled by a water balloon launcher applying an average force of 20 newtons for 0.75 seconds. 168. Calculate the maximum height a 0.75-kg ball will rise if it is kicked straight up with an initial speed of 17 meters per second. 169. Calculate the power required to move a 2,000-kilogram automobile to the top of a 100-meter hill in 15.0 seconds. Express the power both in units of watts and horsepower. 170. Carlos accelerates his 3-kilogram skateboard to a speed of 3.96 m/sec in 3 seconds in a distance of 4 meters. How much work does he do? 171. Which of the circuits pictured below is an open circuit? LORI DUNN 172. If the current moving through the filament of a light bulb is 0.5 amps when the voltage across the bulb is 120 volts, what is the resistance of the bulb? 173. Typically, household appliances operate at 120 volts. What is the current flowing in the circuit of a microwave when the resistance of the microwave oven is 30 ohms? A simple circuit is pictured in Figure 13-1. A light bulb is connected to a 9-volt battery that causes 3 amps of current through the bulb: 174. What is the resistance of the light bulb in the circuit shown in Figure 13-1? 175. If the light bulb in the circuit shown in Figure 13-1 is replaced with a light bulb having a resistance of 9 ohms, what would the new current in the circuit be? 176. If a second 9-volt battery is stacked with the battery shown in the circuit in Figure 13-1, what would the new current in the circuit be? 177. A series circuit contains a 9 volt battery and three resistors of 1 ohm, 3 ohms, and 5 ohms. What is the current in the circuit? LORI DUNN A 0.5-ohm bulb and a 2-ohm bulb are connected in parallel to a 3-volt battery. 178. Draw the circuit diagram, and label the values for voltage and resistance. 179. What is the voltage across each bulb? 180. What is the current through the branch with the 2-ohm bulb? Show your work. 181. What is the current through the branch with the 0.5-ohm bulb? Show your work. 182. What is the total circuit current (ignore the resistance of the wires and batteries)? 183. What is the charge on the object pictured? 184. Two 3-coulomb charged metal spheres are separated by 900 meters. What is the electric force between the metal spheres? 185. Calculate the electric force between a proton and an electron. A proton has a charge of 1.6 x 10-19 coulombs; an electron has a charge of -1.6 x 10-19 coulombs; and they are separated by 3 x 10-11 meters. 186. Two objects of equal charge are repelled by an electrical force of 200 newtons. If the distance separating the objects is 1 meter, what are the charges of the objects? 187. Middle C on a piano has a frequency of about 264 hertz. If the wavelength in air of this note is 1.31 meters, what is the speed of sound in air? 188. On a July day, the waves in the Outer Banks of North Carolina hit the beach every 13 seconds. If the distance between each wave crest is 25 meters, what is the speed of the waves as they travel toward the beach? 189. The magnetron of a microwave oven produces a standing, electromagnetic wave with a frequency of 2.4 x 109 cycles per second. What is the length of one of these standing waves if the speed of an electromagnetic wave is 3.0 x 108 m/sec? 190. A string 3.0 meters long is vibrating at 50 hertz. Calculate the speed of the wave on the string. LORI DUNN Essay 191. Explain why airbags in automobiles help to prevent injury. 192. A 20-gram ball of clay strikes a wooden block (pictured in the diagram) at a speed of 10 cm/sec and sticks to the block. The block wiggles but does not tip over. A 20-gram “bouncy ball” traveling at 10 cm/sec strikes the same block and bounces off in the direction from which it came. This time, the block tips over. Explain why. 193. Explain the following statement: “Applying a force to an object does not necessarily give the object energy.” 194. Describe the three processes that are used to charge objects. Other The circuit pictured contains a light bulb connected to a voltage source that causes 2 amps of current through the bulb. Figure 13-2 195. Draw a circuit diagram to represent the circuit in Figure 13-2 using electrical symbols. 196. Determine the resistance of the light bulb in Figure 13-2. If the statement about a circuit is true for a series circuit, place an “S” in the blank. If the statement is true for a parallel circuit, place a “P” in the blank. 197. ____ There are multiple paths for current. 198. ____ There is only one path for current. LORI DUNN 199. ____ Current is the same at every point in the circuit. 200. ____ Total battery voltage is equal to the sum of the voltages across each resistor. 201. ____ The voltage across each branch is the same and is equal to the battery voltage. The circuit pictured contains 3 identical light bulbs. They are connected to a voltage source which causes 2 amperes of current to flow through each of the bulbs. Figure 14-1 202. Identify the type of circuit in Figure 14-1. 203. Determine the current produced by the source in Figure 14-1. 204. What is the resistance of each bulb in the circuit shown in Figure 14-1? 205. What is the total resistance of the circuit shown in Figure 14-1? 206. Identify the wave interaction represented by each diagram. a. b. c. LORI DUNN 207. Two pulses are traveling on a rope as shown in the diagram. The two pulses meet for an instant. a. Name the type of interference that occurs at that instant. b. Draw a diagram that would represent the rope at the instant the pulses meet. More Problem Solving 208. An elevator provides 654,000 J of work during an 18 s ride. How much power must the motor on the elevator supply? 209. A car engine supplies a power of 300,000 W while traveling at constant speed of 28 m/s. Find the force exerted by the engine. 210. A 5500 W lathe can move an iron block at a constant speed of 4.3 m/s. What is the force applied to the block? 211. A heat engine does 78,000 J of work during 20 minutes. Find the power supplied by the engine. 212. A roller coaster starts from rest at the top of a 90 m hill. How fast will it be going at the bottom of the hill, if there is no friction? 213. A spring gun has a spring constant of 175 N/m. How fast will a 0.02 kg dart go if the spring is compressed 0.015 m? 214. A student uses a spring gun (with a spring constant of 150 N/m) to launch a marble vertically into the air. The mass of the marble is 0.01 kg and the spring is compressed 0.025 m. How high will the marble go? 215. A children’s roller coaster is released from the top of a track. If its maximum speed at ground level is 3 m/s, find the height it was released from. 216. A student uses a spring gun (with a spring constant of 150 N/m) to launch a marble vertically into the air. The mass of the marble is 0.01 kg and the spring is compressed 0.025 m. How high will the marble go? 217. A children’s roller coaster is released from the top of a track. If its maximum speed at ground level is 3 m/s, find the height it was released from. 218. A student runs to physics class with a speed of 7 m/s. If the student has 960 J of kinetic energy, what is her mass? LORI DUNN 219. A spring with spring constant 90 N/m has 14 J of EPE stored in it. How much is it compressed? 220. When a 0.2 kg rock is dropped from a height of 3 m on an asteroid, it loses 0.45 J of GPE. What is the acceleration due to gravity on the asteroid? 221. How much work is required to lift a 1200 kg rock 15 m? 222. Create a bar diagram for: A ball is dropped from rest from a bridge. As the ball falls through the air, it encounters a small amount of air resistance. The final state of the ball is the instant before it strikes the water. 223. Create a bar diagram for: A volleyball player spikes the ball at just above net level and drives it over the net. The initial state is the ball just prior to the spike. The final state of the ball is the instant before it strikes the ground. 224. Consider a roller coaster car in the ideal situation in which the force of air resistance is assumed negligible. The only force doing work on the roller coaster car is gravity. The diagram below depicts the conservation of total mechanical energy and the transformation of potential and kinetic energy for a roller coaster car at five positions along a track. Match the numbered bar diagrams to the appropriate position on the roller coaster. 1 LORI DUNN 2 3 4 5 Answer Section MODIFIED TRUE/FALSE 1. ANS: F (answers acceptable:) remains the same stays the same does not change doesn’t change 2. ANS: F, power 3. ANS: T 4. ANS: F, open 5. ANS: F (voltage, voltage drop or potential difference) 6. 7. 8. 9. 10. 11. 12. 13. 14. ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: F, resistance T F, parallel circuit T T F, decreases F, positive to negative F, conductors T MULTIPLE CHOICE 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: A B D C D B D C A D 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: A B B B B C C B C C 52. 53. 54. 55. 56. 57. ANS: ANS: ANS: ANS: ANS: ANS: B A D C C C 35. 36. 37. 38. 39. 40. 41. 42. 43. ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: D A B B C D C B B 44. ANS: D 45. ANS: B 46. 47. 48. 49. 50. 51. ANS: ANS: ANS: ANS: ANS: ANS: B A C D A A LORI DUNN 58. 59. 60. 61. 62. 63. ANS: ANS: ANS: ANS: ANS: ANS: A B D C C B 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81. 82. ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: D C B B D A B B A C A A B B B C C D A 83. 84. 85. 86. 87. 88. 89. 90. 91. 92. 93. 94. 95. 96. 97. 98. 99. 100. 101. ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: C B C C D D A D D C D C B C C B D B D 102. 103. 104. 105. 106. 107. 108. 109. 110. 111. 112. 113. 114. 115. 116. 117. 118. ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: B D A B D A C D A B A B A D D C B 119. ANS: D 120. ANS: C 121. ANS: A 122. ANS: B 123. ANS: D 124. ANS: B 125. ANS: C 126. ANS: B 127. ANS: A COMPLETION 128. 129. 130. 131. 132. 133. 134. 135. 136. ANS: momentum ANS: impulse ANS: impulse or change in momentum ANS: potential or gravitational potential ANS: mass, speed mass, velocity velocity, mass speed, mass ANS: conservation of energy ANS: kinetic ANS: energy ANS: height 137. 138. 139. 140. 141. 142. 143. 144. 145. 146. 147. 148. ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: circuit circuit diagram switch voltage voltage decreases static net or excess polarized attract neutral electric charge SHORT ANSWER 149. ANS: The forces are the same; the collision involves an action-reaction pair of forces. LORI DUNN 150. ANS: By “following through” you would maintain contact with the ball for a longer time, imparting a greater impulse, more momentum and, therefore, greater speed to the ball. 151. ANS: A. At a height of 2.5 meters above position (1) the kinetic energy will equal the potential energy. B. They both will be zero at those two positions. C. They both will be the same and at their maximums. 152. ANS: The work done by Bik on both days is the same, but she generated more power on Monday as she ran up the stairs. 153. ANS: Circuit diagrams are drawn using symbols to represent the arrangement of components in a circuit because it is easier and quicker than drawing realistic pictures of components. 154. ANS: The flashlight will not work because the voltage, or potential difference, across the two batteries is zero. Instead of the batteries’ voltages adding together, the voltages subtract from each other. 155. ANS: The other two bulbs will go out when one bulb is unscrewed. 156. ANS: An electrically neutral object can either lose negative charge or gain positive charge to become positively charged. 157. ANS: The electrical force between them is a repulsive force, pushing the charges away from each other. 158. ANS: The two factors are the amount of excess charge on the objects and the distance between them. The force is stronger when the amount of charge is greater and when they are closer together. 159. ANS: The force between charges is inversely proportional to the square of the distance between them. Halving the distance increases the force by 4 times. 160. ANS: Charging by friction occurs when two neutral objects are rubbed together, and charge is transferred from one to the other. One object loses negative charge. Objects charged in this manner have opposite charges and attract each other. Examples may vary. Correct examples include: clothes from a dryer, certain semi-precious stones rubbed with fabric, a glass rod rubbed with silk, a person dragging your feet over a floor or carpet 161. ANS: Some of the electrons in conductors are not fixed to individual atoms but are free to move throughout the material. Moving electrons create current. 162. ANS: 163. ANS: reflection, refraction, diffraction, absorption PROBLEM 164. ANS: 165. ANS: speed = 1.3 m/sec Since momentum must be conserved, the momentum of the system before Bozo catches the ball must equal the momentum of the system after Bozo catches the ball. After Bozo catches the ball, the ball, Bozo and the wagon must move off at the same speed. m1 = mass of Bozo and wagon m2 = mass of cannonball v1 = initial speed of Bozo and wagon v2 = speed of cannonball LORI DUNN v’ = speed of all momentum before = momentum after (m1)(v1) + (m2)(v2) = (m1 + m2)(v’) (75 kg + 10 kg)(0 m/sec) + (8 kg)(15 m/sec) = (75 kg + 10 kg + 8 kg)(vbc) 0 + 120 kg·m/sec = 93 kg(vbc) vbc = 1.3 m/sec 166. ANS: The momentum of the wagon must be reduced to zero to stop it. impulse = change in momentum Ft = m(v2 - v1) = (200 kg)(4.5 m/sec - 0) = 900 kg·m/sec, or 900 newton-seconds 167. ANS: 168. ANS: maximum height = 14.7 meters potential energy = kinetic energy 169. ANS: power = 130,667 watts = 175 horsepower power = = power = power = 170. ANS: 15.8 joules 171. ANS: A 172. ANS: LORI DUNN = = 130,667 watts = 175 horsepower 173. ANS: 174. ANS: 175. ANS: 176. ANS: 177. ANS: 178. ANS: 179. ANS: A parallel circuit has constant voltage in each branch, therefore the voltage across each bulb is 3 volts. 180. ANS: 181. ANS: 182. ANS: 1.5 amperes + 6 amperes = 7.5 amps 183. ANS: The charge on the object is -5. positive charge + negative charge = net (or excess) charge +10 + (-15) = -5 184. ANS: 185. ANS: LORI DUNN 186. ANS: 187. ANS: 346 m/sec 188. ANS: 1.9 m/sec 189. ANS: 1.25 x 10-1 meters (or 0.125 meters) 190. ANS: 75 meters/second Frequency is given as 50 hertz. In the 4th harmonic, there are two complete waves on the 3.0 meter string. Wavelength is therefore 1.5 meters. ESSAY 191. ANS: In automobile accidents, passengers as well as drivers continue to travel in a straight line after the car has slowed drastically or even stopped quickly due to a collision. They often make contact with surfaces in the car that are very hard. A hard surface applies a large force over a short time to reduce velocity and momentum to zero. The airbag allows a smaller force to be applied over a longer time, resulting in the same impulse and change in momentum but with less serious injuries. 192. ANS: As the ball and block collide, momentum of the ball-block system must be conserved. As the clay ball strikes the block and stops, it imparts its momentum to the block. While momentum is conserved, its mass times its change of velocity (impulse) is not sufficient to topple the block. The bouncy ball behaves in a similar manner EXCEPT that in striking the block and bouncing back, it experiences a greater change in velocity because it has changed direction as well. Because its change in velocity is nearly twice as great, it imparts nearly twice the momentum (impulse) to the block, enough to topple the block. LORI DUNN 193. ANS: For mechanical energy to be transferred to an object, work must be done on the object. Work is the product of force AND the distance the object moves in the direction of the applied force. It is possible to apply a force on an object with no resulting movement. Unless the object moves when the force is applied, no mechanical energy is absorbed by the object. 194. ANS: 1) Charge by induction: No contact is made between the charged object and the object being charged. Placing the charged object close by forces electrons to move in the object being charged. Grounding the object being charged causes electrons to move into or out of it and allows it to have a net charge. The original object’s net charge does not change. 2) Charge by friction: By rubbing two objects together, electrons are transferred between the two objects. One object gains electrons and has a negative net charge. One object loses electrons and has a positive net charge. 3) Charge by contact: Contact is made between a charged object and a neutral object. Electrons are transferred between the two objects and the neutral object becomes charged. OTHER 195. ANS: 196. ANS: 197. 198. 199. 200. 201. 202. 203. 204. ANS: P ANS: S ANS: S ANS: S ANS: P ANS: It is a parallel circuit. ANS: currenttotal = current1 + current2 + current3; currenttotal = 6 amps ANS: Each bulb is identical and the current for each bulb is 2 amps The voltage for the circuit is 3 volts resistance = voltage ÷ current resistance = (3 volts) ÷ (2 amps) resistance = 1.5 ohms 205. ANS: LORI DUNN 206. ANS: a. refraction b. reflection 207. ANS: a. constructive; b. (See diagram below) 208. P = W / t P = 654,000 J / 18 s P = 36,333 W 209. P = F v F=P/v F = 300,000 W / 28 m/s F = 10,714 N 210. P = F v F=P/v F = 5500 W / 4.3 m/s F = 1279 N 211. 20 minutes x (60 seconds / minute) = 1200 s P=W/t P = 78,000 J / 1200 s P = 65 W 212. GPE = KE m g h = ½ m v2 v2 = 2 g h v2 = 2 (9.8 m/s2) 90 m v = 42 m/s 213. EPE = KE ½ k x2 = ½ m v2 v2 = k x2 / m v2 = 175 N/m (0.015 m)2 / 0.02 kg v = 1.4 m/s 214. EPE = GPE ½ k x2 = m g h h = ½ k x2 / m g h = ½ 150 N/m (0.025 m)2 / 0.01 kg 9.8 m/s2 h = 0.048 m 215. GPE = KE m g h = ½ m v2 h = v2 / (2 g) LORI DUNN c. diffraction h = (3 m/s)2 / 2 (9.8 m/s2) h = 0.46 m 216. EPE = GPE ½ k x2 = m g h h = ½ k x2 / m g h = ½ 150 N/m (0.025 m)2 / 0.01 kg 9.8 m/s2 h = 0.048 m 217. GPE = KE m g h = ½ m v2 h = v2 / (2 g) h = (3 m/s)2 / 2 (9.8 m/s2) h = 0.46 m 218. KE = ½ m v2 m = 2 KE / v2 m = 2 (960 J) / (7 m/s)2 m = 39.2 kg 219. EPE = ½ k x2 x2 = 2 EPE / k x2 = 2 14 J / 90 N/m x= 0.31 m 220. GPE = m g h g = GPE / (m h) g = 0.45 J / (0.2 kg 3 m) g = 0.75 m/s2 221. F = m g W=Fd W=mgd W = 1200 kg 9.8 m/s2 15 m W = 176,400 J 222. LORI DUNN (or GPE = mgh) 223. 224. A: 3; B: 4; C: 5; D: 1; E: 2 LORI DUNN