Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Horses with the greatest linear speed on a merry-go-round are located 1) A) near the center. B) anywhere, because they all move at the same speed. C) near the outside. 2) Which horse moves faster in m/s on a merry-go-round? 2) A) one near inner rail B) both move at the same speed in m/s. C) one near outer rail 3) If a turntable's rotational speed is doubled, then the linear speed of a pet hamster sitting on the edge of the record will A) halve. B) remain the same. C) double. 4) Your pet hamster sits on a record player that has constant angular speed. If the hamster moves to a point twice as far from the center, then its linear speed A) halves. B) remains the same. C) doubles. 5) When railroad tracks make a curve, the outer track is longer. This means a wheel that rides on the outer track needs to somehow A) maintain the same speed as the wheel on the inner track. B) roll faster than the wheel on the inner track. C) roll slower than the wheel on the inner track. 3) 4) 5) 6) When a train makes a curve, a tapered wheel rim is able to 6) A) reduce differences in angular speeds. B) cover different distances per revolution. C) maintain a fixed rotational speed. 7) Each rolling wheel of a railroad train is tapered. Compared with the wide part, the narrow part of the wheel has a tangential speed that is A) less. B) greater. C) the same for both. 7) 8) The tapered shape of the wheel rims that ride on railroad tracks allows opposite wheels to 8) A) travel at different linear speeds for the same rotational speed. B) in effect, vary their diameters. C) both of these D) none of these 9) The circumference of a bicycle wheel is 2 meters. If it rotates at 1 revolution per second then its linear speed is A) 1 m/s. B) 3.14 m/s. C) 3 m/s. D) 6.28 m/s. E) 2 m/s. 9) 1
10) Consider a string with several rocks tied along its length at equally spaced intervals. You whirl the string overhead so that the rocks follow circular paths. Compared with a rock at the end of the string, a rock at the middle moves A) half as fast. B) at the same linear speed. C) twice as fast. 10) 11) The net force exerted on a car traveling in a circular path at constant speed is 11) A) directed forward, in the direction of travel. B) zero because the car is not accelerating. C) directed toward the center of the curve. D) none of the above 12) If you're on a Ferris wheel at a carnival, seated 10 m from the Ferris wheel's axis that makes a complete rotation each minute, your linear speed is A) 10 m/min. B) 62.8 m/min. C) 31.4 m/min. D) 100 m/min. E) need more information 12) 13) The rotational inertia of your leg is greater when your leg is 13) A) bent. B) straight. C) same either way 14) You can swing your legs to and fro more frequently when your legs are 14) A) same either way B) straight. C) bent. 15) An industrial flywheel has a greater rotational inertia when most of its mass is 15) A) uniformly spread out as in a disk. B) nearer the rim. C) nearer the axis. 16) The rotational inertia of a pencil is greatest about an axis 16) A) about its midpoint, like a propeller. B) about its end, like a pendulum. C) along its length, where the lead is. 17) Which of these animals has a quicker stride? 17) A) cat B) mouse C) horse D) giraffe 18) A tightrope walker more easily balances on a tight wire if her pole 18) A) is short but heavy. B) droops. C) is held high. 19) Consider two flywheels of the same size and shape, but one with twice the mass. Rotational inertia of the more massive one is A) two times greater. B) four times greater. C) half. D) the same as the other one. 19) 2
20) A flywheel's diameter is twice that of another of the same shape and mass. Rotational inertia of the larger flywheel is A) four times greater. B) half. C) the same as the other's. D) two times greater. 20) 21) A coin and a ring roll down an incline at the same time. The one to first reach the bottom is the 21) A) ring. B) coin. C) both reach the bottom at the same time 22) A ring and a disk both at rest roll down a hill together. Which rolls slower? 22) A) disk B) both roll at the same speed C) ring D) depends on the masses E) need more information 23) A ring, a disk, and a solid sphere begin rolling down a hill together. Which reaches the bottom first? A) disk B) ring C) all reach the bottom at the same time D) sphere E) need more information 24) Stand a meterstick on its end and let it rotate to the floor. If you attach a heavy glob of clay to its upper end and repeat, the time to fall will be A) shorter. B) the same. C) longer. 23) 24) 25) A vertically-held sledge hammer is easier to balance when the heavier end is 25) A) the same either way B) on your hand. C) at the top, away from your hand. 26) Stand a broom upright on the end of its pole and let it topple to the floor. Repeat, but with the bristles end on the floor. The faster fall will be the broom standing on its A) bristles-end. B) the same either way C) pole-end. 27) Which jar will roll down an incline in the shortest time, an empty one or one filled with peanut butter? A) both reach the bottom at the same time B) the filled jar C) the empty jar D) need more information 28) Which tin can will roll down an incline in the shortest time, one filled with water or one filled with ice? (Hint: water 'slides' inside the can.) A) both the same B) with water C) with ice D) need more information 26) 27) 28) 3
29) Compared with a force, a torque involves 29) A) distance from an axis of rotation. B) leverage. C) rotation. D) all the above 30) A torque acting on an object tends to produce 30) A) velocity. B) linear motion. C) a center of gravity. D) equilibrium. E) rotation. 31) If Alex wishes to rotate his skateboard, then he must apply a 31) A) rotational maneuver. B) pause before bearing down on the board. C) torque. 32) A ball that gains speed as it rolls down a hill experiences a 32) A) net torque. B) net force. C) both of these D) neither of these 33) If you place a pipe over the end of a wrench when trying to rotate a stubborn bolt, effectively making the wrench handle twice as long, you'll multiply the torque by A) four. B) two. C) eight. 33) 34) For a system in mechanical equilibrium, the resultant 34) A) torque must be zero. B) force must be zero. C) both of these D) none of these 35) A ball gains speed while rolling down a hill due mainly to 35) A) its rotational inertia. B) a balanced torque. C) an unbalanced torque. D) its angular acceleration. 36) To rotate a stubborn screw, it is best to use a screwdriver that has a 36) A) long handle. B) smooth handle. C) wide handle. D) none of the above 37) Two people are balanced on a seesaw. If one person leans inward toward the center of the seesaw, that person's end of the seesaw tends to A) rise. B) stay at the same level. C) fall. D) need more information 37) 38) On a balanced seesaw, a boy three times as heavy as his partner sits 38) A) more than 1/3 the distance from the fulcrum. B) less than 1/3 the distance from the fulcrum. C) 1/3 the distance from the fulcrum. 39) A solitary boy cannot balance on a seesaw with its fulcrum at its midpoint. If the fulcrum is moved to one-quarter the distance from the boy, balance is achieved when the weight of the boy is A) equal to the weight of the seesaw. B) less than the weight of the seesaw. C) more than the weight of the seesaw. D) need more information 39) 4
40) A boy plays solitary seesaw by placing the seesaw's fulcrum one-eighth the distance from where he sits at one end. Which weighs more? A) the seesaw B) they have equal weights C) the boy D) need more information 40) 41) Toss a baseball bat into the air and it wobbles about its 41) A) heavier end. B) geometrical center. C) center of mass. 42) The long, heavy tail of a spider monkey enables the monkey to easily vary its 42) A) momentum. B) weight. C) inertia. D) center of gravity. E) none of the above 43) The center of mass of a human body is located at a point that 43) A) is fixed, but different for different people. B) changes as a person bends over. C) is always directly behind the belly button. D) none of the above 44) The famous Leaning Tower of Pisa doesn't topple over because its center of gravity is 44) A) stabilized by its structure. B) displaced from its center. C) in the same place as its center of mass. D) above a place of support. E) relatively low for such a tall building. 45) Which of these has its center of mass where no mass exists? 45) A) basketball B) baseball C) golf ball D) none of the above 46) If Earth had a pair of identical moons on opposite sides of the same circular orbit, the center of gravity of the double-moon-earth system would be A) outside the Earth, but beyond the orbital path of the moons. B) outside the Earth, but within the orbital path of the moons. C) inside the Earth, but off center. D) at the center of the Earth. 46) 47) To kick a football so it won't topple end over end, kick it so the force of impact extends 47) A) above its center of gravity. B) below its center of gravity. C) through its center of gravity. 48) If Earth rotated more slowly about its axis, your weight would 48) A) stay the same. B) be zero. C) increase. D) decrease. 49) Strictly speaking, to weigh less in the Northern Hemisphere, you should move to a location farther 49) A) west. B) south (toward the equator). C) north (toward the pole). D) east. 5
50) When riding at constant velocity on a Segway electric vehicle, your center of mass is 50) A) directly above the point between wheels below. B) slightly in front of the point between wheels below. C) slightly behind the point between wheels below. 51) A 1-kg rock is suspended from the tip of a horizontal meterstick at the 0-cm mark so that the meterstick barely balances like a seesaw when its fulcrum is at the 25-cm mark. From this information, the mass of the meterstick is A) 1 kg. B) 3/4 kg. C) 1/4 kg. D) 1/2 kg. E) none of the above 52) A 1-kg rock is suspended from the tip of a horizontal meterstick at the 0-cm mark so that the meterstick barely balances like a seesaw when its fulcrum is at the 12.5-cm mark. From this information, the mass of the meterstick is A) 1 kg. B) 1/2 kg. C) 3/4 kg. D) 1/4 kg. E) none of the above 53) You can safely stand on the overhanging end of a heavy plank that rests on a table. How much overhang depends on your mass and the plank's mass. If you can stand on the end of a plank that overhangs the edge of the supporting table 1/4 its total length, how massive is the plank compared to your mass? A) 4 times B) 1/2 C) the same D) twice E) 1 and 1/2 times 54) You can safely stand on the overhanging end of a heavy plank that rests on a table. How much overhang depends on your mass and the mass of the plank. If you can stand on the end of a plank that overhangs the edge of the supporting table 1/5 its total length, how massive is the plank compared to your mass? A) more than 1 and 1/3 times B) the same C) 1/3 D) 2/3 E) 1 and 1/3 times 55) If you balance a broom horizontally on one finger, the center of gravity of the broom will be above your finger, closer to the bristles end than the handle end. If you saw the broom in two pieces at that point and weigh the two parts on a scale, you'll find that the heavier part is the A) bristles part. B) handle part. C) both the same weight 51) 52) 53) 54) 55) 6
56) The main reason a person weighs less at the equator than at the poles involves the 56) A) law of action and reaction. B) spin of the Earth. C) influence of the Sun, Moon, and all the planets. 57) Centrifugal forces are an apparent reality to observers in a reference frame that is 57) A) moving at constant velocity. B) rotating. C) an inertial reference frame. D) at rest. E) none of the above 58) The force responsible for a car moving steadily along a no-friction icy banked curve is due to 58) A) the normal force at right angles to the curved surface. B) the radial component of the normal force. C) centrifugal effects. D) none of the above 59) Centripetal force does no work on a circularly-moving object because 59) A) no change in energy occurs. B) centripetal force has no component in the direction of motion. C) rotational energy transfers to kinetic energy. D) none of the above. 60) The bob of a conical pendulum swings in a 60) A) chaotic path. B) to-and-fro path. C) circular path. 61) A difference between linear momentum and angular momentum involves 61) A) two types of speed. B) a radial distance. C) both of these D) neither of these 62) Multiply the equation for linear momentum by radial distance r and you have 62) A) angular momentum. B) rotational kinetic energy. C) rotational inertia. 63) The gravitational field simulated by rotation in a space habitat that is best suited for humans is 63) A) zero. B) one-quarter g. C) three-quarters g. D) one-half g. E) g. 64) A swimming area in a rotating space habitat is located in a region of 1/4 g. If a diver can jump 1 m high in a 1-g region, how high can the same diver jump in the swimming area? A) 1 m B) 16 m C) more than 16 m D) 2 m E) 4 m 64) 7
65) If the rotational speed of a rotating habitat in space increases, the weight experienced by occupants 65) A) stays the same. B) increases. C) is always zero. D) decreases. 66) When a twirling ice skater brings her arms inward, her rotational speed 66) A) increases. B) remains the same. C) decreases. 67) The chef at the infamous Fattening Tower of Pizza tosses a spinning disk of uncooked pizza dough into the air. The disk becomes wider during its flight, while its rotational speed A) slows. B) quickens. C) remains constant. 67) 68) When you do somersaults, you'll more easily rotate when your body is 68) A) straight with both arms above your head. B) curled into a ball shape. C) no difference D) straight with both arms at your sides. 69) As a huge rotating cloud of particles in space gravitate together forming an increasingly dense ball, it shrinks in size and A) rotates at the same speed. B) rotates faster. C) rotates slower. D) cannot rotate. 69) 70) If the planet Jupiter underwent gravitational collapse, its rate of rotation about its axis would 70) A) stay the same. B) decrease. C) increase. D) need more information 71) As the polar icecaps melt, the resulting water spreads over the entire Earth. This new mass distribution tends to make the length of a day A) longer. B) shorter. C) none of these 72) As you crawl toward the edge of a large freely-rotating horizontal turntable in a carnival funhouse, the angular momentum of you and the turntable A) remains the same, but the revolutions per minute decrease. B) increases. C) decreases. D) decreases in direct proportion to your decrease in revolutions per minute. E) none of these 71) 72) 8
Answer Key Testname: UNTITLED2 1) C 2) C 3) C 4) C 5) B 6) B 7) A 8) C 9) E 10) A 11) C 12) B 13) B 14) C 15) B 16) B 17) B 18) B 19) A 20) A 21) B 22) C 23) D 24) C 25) C 26) A 27) B 28) B 29) D 30) E 31) C 32) C 33) B 34) C 35) C 36) C 37) A 38) C 39) C 40) C 41) C 42) D 43) B 44) D 45) A 46) D 47) C 48) C 49) B 50) A 9
Answer Key Testname: UNTITLED2 51) A 52) E 53) C 54) D 55) A 56) B 57) B 58) B 59) B 60) C 61) C 62) A 63) E 64) E 65) B 66) A 67) A 68) B 69) B 70) C 71) A 72) A 10