1. Two cars are moving around a circular track at the same constant speed. If car 1 is at the inner edge of the track and car 2 is at the outer edge, then:
A. the acceleration of car 1 is less than the acceleration of car two.
B. the accelerations of both cars are equal and greater than zero.
C. the acceleration of car 1 is greater than the acceleration of car 2.
D. the accelerations of both cars are zero.
2. Jim exerts a force of 500 N against a 100-kg desk that does not move. Virgil exerts a force of 400 N against a 60-kg desk that moves 2 m in the direction of the push. Mik exerts a force of 200 N against a 50-kg desk that moves 4 m in the direction of the push. The most work is done by:
A. Jim.
B. Virgil.
C. Mik.
D. Virgil and Mik, who do equal amounts of work.
3. A parachutist jumping from an airplane reaches a terminal velocity when the force of air resistance is 490 N. The mass of the parachutist is:
A. 490 kg.
B. 9.8 kg.
C. 40 kg.
D. 50 kg.
E. 80 kg.
4. A child riding on a swing rises to a height 1.0 m above the lowest point. Another child of equal mass whose speed at the lowest point is twice as great will rise:
A. to the same height.
B. twice as high.
C. four times as high.
D. to a height which depends on the mass.
5. A dog weighs 250 N. What is his approximate weight in pounds (lb)?
A. 250 lb
B. 100 lb
C. 55 lb
D. 32 lb
E. 25 lb
6. An elevator is being lifted upward at a constant speed by a steel cable. All frictional forces are neglected. In this situation, forces on the elevator are such that:
A. the upward force by the cable is greater than the downward force of gravity.
B. the upward force by the cable is equal to the downward force of gravity.
C. the upward force by the cable is smaller than the downward force of gravity.
D. none of the above. (The elevator goes up because the cable is being shortened, not because an upward force is exerted on the elevator by the cable.)
7. On a two-lane highway (not divided), a car headed north experiences a centripetal acceleration directed toward the east. Simultaneously, a truck passes the car, headed south in the other lane. The direction of the centripetal acceleration on the truck is:
A. west.
B. east.
C. north.
D. south.
8. A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force doing no work during the motion is:
A. gravity.
B. friction.
C. the applied force.
9. A book weighing 10 N is held at rest in the palm of the hand. The reaction to the force of the hand on the book is a force of:
A. 10 N exerted by the Earth on the book.
B. 10 N exerted by the book on the Earth.
C. 10 N exerted by the book on the hand.
D. 0 N.
10. Which has the greater kinetic energy: a 1-ton car moving at 30 m/s, or a half-ton car moving at 60 m/s?
A. a 1-ton car
B. a half-ton car
C. both have same kinetic energy
11. Car A travels with speed v around curve number one, which has a radius r. Car B travels with speed 2v around curve number two, which has a radius 2r. The acceleration will be:
A. zero for both cars.
B. the same for both cars.
C. greater for car A.
D. greater for car B.
12. The centripetal force of an object in uniform circular motion:
A. is a directed tangent to the circle.
B. Points away from the center of the circle.
C. Points toward the center of the circle.
D. None of the above
E. All of the above
13. A body on the Earth has a mass of 20 kg. The same body in outer space will have a mass of ____________ kg.
A. 20
B. 30
C. 3.7
D. 1
14. In the case of uniform circular motion:
A. the velocity of the object is constant.
B. the speed of the object is constant.
C. The net force of the object is zero.
D. The radius is continually changing.
E. None of the above
15. A ball is whirled on the end of a string in a horizontal circle at constant speed. Suddenly, the string breaks. Immediately after the string breaks, the ball will:
A. move horizontally outward from the center of the circle.
B. move horizontally inward toward the center of the circle.
C. drop straight down.
D. have a horizontal velocity that is tangential to the circle.
16. If the radius in which an object moves in uniform circular motion is doubled while the speed remains constant the centripetal force is multiplied by a factor of:
A. 4.
B. 2.
C. 1.
D. . 5.
E. . 25.
17. A wooden block slides down a rough incline. Which of the following statements is true?
A. The kinetic energy of the block is decreasing.
B. The gravitational potential energy of the block is increasing.
C. The mechanical energy of the block is constant.
D. The mechanical energy of the block is increasing.
E. The mechanical energy of the block is decreasing.
18. Which of the following is not a unit of power?
A. watt
B. kilowatt
C. kilowatt-hour
D. joule/second
E. horsepower
19. A cyclist races around a circular track at the constant speed of 20 m/s. The radius of the track is 50 m. The acceleration of the cyclist is:
A. zero.
B. 8 m/s2, toward the center of the track.
C. 10 m/s2, downward.
D. 20 m/s2, in the direction of travel.
20. An object with a kinetic energy of 50 J is stopped in a distance of 0.01 m. The average force that stops the object is:
A. 0.5 N.
B. 50 N.
C. 500 N.
D. 5,000 N.
E. 50,000 N.
21. A pendulum swings through 10 cycles in 5 seconds. The frequency of the pendulum is:
A. 10 Hz.
B. 5 Hz.
C. 2 Hz.
D. 0.5 Hz.
E. 0.1 Hz.
22. A ball at the end of a string is swinging as a simple pendulum. Assuming no loss in energy due to friction, we can say for the ball that:
A. the potential energy is maximum at the lowest position of the ball.
B. the potential energy is maximum where the kinetic energy is a minimum.
C. the potential energy is maximum where the kinetic energy is maximum.
D. the kinetic energy is maximum at each end of the motion.
23. A car travels around a curve with constant speed. Choose the correct statement from the following.
A. The velocity of the car is constant.
B. The car has an acceleration directed inward toward the center of the curve.
C. The car has an acceleration directed outward from the center of the curve.
D. The car has zero acceleration.
E. The car has an acceleration directed in the instantaneous direction of the velocity vector.
24. Suppose one’s hand exerts a force of 12 N upward on a book weighing 10 N. The reaction to the force of the hand on the book is a force of:
A. 10 N exerted by the Earth on the book.
B. 10 N exerted by the book on the Earth.
C. 12 N exerted by the book on the hand.
D. 10 N exerted by the book on the hand.
E. 2 N exerted by the book on the hand.
25. If the speed of an object in uniform circular motion is doubled while the radius remains contact the centripetal force is multiplied by a factor of:
A. 4.
B. 3.
C. 1.
D. . 5.
E. . 25.
