Download Exam Name MULTIPLE CHOICE. Choose the one alternative that

Exam
Name __________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Can work be done on a system if there is no motion?
1)
A) No, because of the way work is defined.
B) Yes, since motion is only relative.
C) No, since a system which is not moving has no energy.
D) Yes, if an outside force is provided.
2) Does the centripetal force acting on an object do work on the object?
2)
A) No, because the force and the displacement of the object are perpendicular.
B) Yes, since it takes energy to turn an object.
C) No, because the object has constant speed.
D) Yes, since a force acts and the object moves, and work is force times distance.
3) The area under the curve, on a Force versus position (F vs. x) graph, represents
A) work.
B) kinetic energy.
C) potential energy.
D) power.
3)
4) If the net work done on an object is positive, then the object's kinetic energy
A) is zero.
B) remains the same.
C) decreases.
D) increases.
4)
5) A truck weighs twice as much as a car, and is moving at twice the speed of the car. Which
statement is true about the truck's kinetic energy compared to that of the car?
5)
A) The truck has 8 times the kinetic energy of the car.
B) All that can be said is that the truck has more kinetic energy.
C) The truck has 4 times the kinetic energy of the car.
D) The truck has twice the kinetic energy of the car.
6) A freight car moves along a frictionless level railroad track at constant speed. The car is open on
top. A large load of coal is suddenly dumped into the car. What happens to the velocity of the car?
6)
A) It remains the same.
B) It increases.
C) It decreases.
D) cannot be determined from the information given
7) A child falls sideways off a sled while sledding on frictionless ice. What happens to the velocity of
the sled?
A) It remains the same.
B) It decreases.
C) It increases.
D) cannot be determined from the information given
A-l
7)
8) A small car meshes with a large truck in a head-on collision. Which of the following statements
concerning the magnitude of the average collision force is correct?
A) The small car and the truck experience the same average force.
B) The truck experiences the greater average force.
C) The small car experiences the greater average force.
D) It is impossible to tell since the masses and velocities are not given.
8)
9) Two objects collide and bounce off each other. Linear momentum
A) is definitely not conserved.
B) is conserved only if the collision is elastic.
C) is conserved only if the environment is frictionless.
D) is definitely conserved.
9)
10) When is kinetic energy conserved?
A) in any collision in which the objects do not stick together
B) in all collisions
C) in inelastic collisions
D) in elastic collisions
10)
11) A boy and a girl are riding on a merry-go-round which is turning at a constant rate. The boy is
near the outer edge, and the girl is closer to the center. Who has the greater angular displacement?
A) the boy
B) the girl
C) Both have the same non-zero angular displacement.
D) Both have zero angular displacement.
11)
12) A boy and a girl are riding on a merry-go-round which is turning at a constant rate. The boy is
near the outer edge, and the girl is closer to the center. Who has the greater angular speed?
A) the girl
B) the boy
C) Both have the same non-zero angular velocity.
D) Both have zero angular velocity.
12)
13) A boy and a girl are riding on a merry-go-round which is turning at a constant rate. The boy is
near the outer edge, and the girl is closer to the center. Who has the greater linear speed?
A) the girl
B) the boy
C) Both have the same non-zero translational velocity.
D) Both have zero translational velocity.
13)
14) Two equal forces are applied to a door. The first force is applied at the midpoint of the door; the
second force is applied at the doorknob. Both forces are applied perpendicular to the door. Which
force exerts the greater torque?
A) both exert zero torques
B) the second at the doorknob
C) both exert equal non-zero torques
D) the first at the midpoint
14)
A-2
15) Suppose a solid sphere of mass M and radius R rolls without slipping down an inclined plane
starting from rest. The angular velocity of the sphere at the bottom of the incline depends on
15)
A) the mass of the sphere.
B) both the mass and the radius of the sphere.
C) the radius of the sphere.
D) neither the mass nor the radius of the sphere.
16) What force is needed to make an object move in a circle?
A) static friction
B) weight
16)
C) centripetal force
D) kinetic friction
17) In the absence of an external force, a moving object will
17)
A) stop immediately.
B) slow down and eventually come to a stop.
C) move with constant velocity.
D) go faster and faster.
18) Which of Newton's laws best explains why motorists should buckle-up?
A) the first law
B) the law of gravitation
C) the second law
D) the third law
18)
19) When a football in a field goal attempt reaches its maximum height, how does its speed compare to
its initial speed?
A) It is zero.
B) It is greater than its initial speed.
C) It is equal to its initial speed.
D) It is less than its initial speed.
20) At what angle should a water-gun be aimed in order for the water to land with the greatest
horizontal range?
A)0°
B)60°
C)30°
A-3
D)45°
19)
20)
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