Question 1

A golf ball is struck by a golf club and falls on a green eight feet above the tee.The potential energy of the Earth-ball system is greatest:

Accepted Answer

A)  just before the ball is struck
B)  just after the ball is struck
C)  just after the ball lands on the green
D)  when the ball comes to rest on the green
E)  when the ball reaches the highest point in its flightF) None of the above
G) B) and D)

Question 2

The potential energy of a 0.20-kg particle moving along the x axis is given by U(x) = (8.0 J/m2) x2 − (2.0 J/m4) x4.When the particle is at x = 1.0 m the magnitude of its acceleration is:

Accepted Answer

A)  0 m/s2
B)  -8 m/s2
C)  8 m/s2
D)  -40 m/s2
E)  40 m/s2F) B) and E)
G) B) and C)

Question 3

A 0.50-kg block attached to an ideal spring with a spring constant of 80 N/m oscillates on a horizontal frictionless surface.The total mechanical energy is 0.12 J.The greatest extension of the spring from its equilibrium length is:

Accepted Answer

A)  1.5 *10-3 m
B)  3.0*10-3 m
C)  0.039 m
D)  0.055 m
E)  18 mF) None of the above
G) B) and D)

Question 4

The thermal energy of a system consisting of a thrown ball, Earth, and the air is most closely associated with:

Accepted Answer

A)  the gravitational interaction of the Earth and the ball
B)  the kinetic energy of the ball as a whole
C)  motions of the individual particles within the ball
D)  motions of individual particles within the ball and the air
E)  the kinetic energy of Earth as a wholeF) B) and C)
G) A) and E)

Question 5

A 6.0-kg block is released from rest 80 m above the ground.When it has fallen 60 m its kinetic energy is approximately:

Accepted Answer

A)  4700 J
B)  3500 J
C)  1200 J
D)  120 J
E)  60 JF) B) and E)
G) A) and D)

Question 6

A block slides across a rough horizontal table top.The work done by friction changes:

Accepted Answer

A)  only the kinetic energy
B)  only the potential energy
C)  only the thermal energy
D)  only the kinetic and potential energies
E)  only the kinetic and thermal energiesF) C) and D)
G) None of the above

Question 7

A small object of mass m, on the end of a light cord, is held horizontally at a distance r from a fixed support as shown.The object is then released.What is the tension in the cord when the object is at the lowest point of its swing?

Accepted Answer

A)  mg/2
B)  mg
C)  2 mg
D)  3 mg
E)  mgrF) A) and E)
G) B) and C)

Question 8

The sum of the kinetic and potential energies of a system of objects is conserved:

Accepted Answer

A)  only when no external force acts on the objects
B)  only when the objects move along closed paths
C)  only when the work done by the resultant external force is zero
D)  always
E)  none of the aboveF) B) and D)
G) D) and E)

Question 9

The diagram shows a plot of the potential energy as a function of x for a particle moving along the x axis.The points of neutral equilibrium are:

Accepted Answer

A)  only a
B)  only b
C)  only c
D)  only d
E)  b and dF) None of the above
G) C) and D)

Question 10

A nonconservative force:

Accepted Answer

A)  violates Newton's second law
B)  violates Newton's third law
C)  cannot do any work
D)  must be perpendicular to the velocity of the particle on which it acts
E)  none of the aboveF) A) and C)
G) C) and E)

Question 11

No kinetic energy is possessed by:

Accepted Answer

A)  a shooting star
B)  a rotating propeller on a moving airplane
C)  a pendulum at the bottom of its swing
D)  an elevator standing at the fifth floor
E)  a cycloneF) C) and D)
G) A) and B)

Question 12

A 700-N man jumps out of a window into a fire net 10 m below.The net stretches 2 m before bringing the man to rest and tossing him back into the air.The maximum potential energy of the net, compared to its unstretched potential energy, is:

Accepted Answer

A)  300 J
B)  710 J
C)  850 J
D)  7000 J
E)  8400 JF) A) and C)
G) None of the above

Question 13

A stationary mass m = 1.3 kg is hanging from a spring of spring constant k = 1200 N/m.You raise the mass a distance of 10 cm above its equilibrium position.How much has the potential energy of the mass-spring system changed?

Accepted Answer

A)  1.3 J
B)  6.0 J
C)  7.3 J
D)  12 J
E)  13 JF) C) and E)
G) A) and B)

Question 14

A 0.5-kg block slides along a horizontal frictionless surface at 2 m/s.It is brought to rest by compressing a very long spring of spring constant 800 N/m.The maximum spring compression is:

Accepted Answer

A)  0.6 cm
B)  3 cm
C)  5 cm
D)  7 cm
E)  8 cmF) A) and E)
G) C) and E)

Question 15

A 2-kg block is thrown upward from a point 20 m above the Earth's surface.At what height above Earth's surface will the gravitational potential energy of the Earth-block system have increased by 500 J?

Accepted Answer

A)  5 m
B)  25 m
C)  46 m
D)  70 m
E)  270 mF) B) and E)
G) All of the above

Question 16

A good example of kinetic energy is provided by:

Accepted Answer

A)  a wound-up clock spring
B)  the raised weights of a grandfather's clock
C)  a tornado
D)  a gallon of gasoline
E)  an automobile storage batteryF) B) and D)
G) A) and E)

Question 17

A stationary mass m = 1.3 kg is hanging from a spring of spring constant k = 1200 N/m.You raise the mass a distance of 10 cm above its equilibrium position in a time of 1.4 s.What was the average power expended?

Accepted Answer

A)  0.93 W
B)  4.3 W
C)  5.2 W
D)  8.6 W
E)  10.2 WF) A) and D)
G) A) and E)

Question 18

The graphs below show the magnitude of the force on a particle as the particle moves along the positive x axis from the origin to x = x1.The force is parallel to the x axis and is conservative.The maximum magnitude F1 has the same value for all graphs.Rank the situations according to the change in the potential energy associated with the force, least (or most negative) to greatest (or most positive) . 1.The force is parallel to the x axis and is conservative.The maximum magnitude F1 has the same value for all graphs.Rank the situations according to the change in the potential energy associated with the force, least (or most negative) to greatest (or most positive) .   A) 3, 1, 2 B) 1, 3, 2 C) 2, 3, 1 D) 3, 2, 1 E) 2, 1, 3" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  3, 1, 2
B)  1, 3, 2
C)  2, 3, 1
D)  3, 2, 1
E)  2, 1, 3F) B) and E)
G) B) and D)

Question 19

A ball is held at a height H above a floor.It is then released and falls to the floor.If air resistance can be ignored, which of the five graphs below correctly gives the mechanical energy E of the Earth-ball system as a function of the altitude y of the ball?

Accepted Answer

A)  I
B)  II
C)  III
D)  IV
E)  VF) C) and D)
G) A) and B)

Question 20

The diagram shows a plot of the potential energy as a function of x for a particle moving along the x axis.The points of unstable equilibrium are:

Accepted Answer

A)  only a
B)  only b
C)  only c
D)  only d
E)  b and dF) A) and B)
G) C) and D)

Exam 8: Potential Energy and Conservation of Energy

A small object of mass m, on the end of a light cord, is held horizontally at a distance r from a fixed support as shown.The object is then released.What is the tension in the cord when the object is at the lowest point of its swing?

Correct Answer
verified

A ball is held at a height H above a floor.It is then released and falls to the floor.If air resistance can be ignored, which of the five graphs below correctly gives the mechanical energy E of the Earth-ball system as a function of the altitude y of the ball?

Correct Answer
verified

No kinetic energy is possessed by:

Correct Answer
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A nonconservative force:

Correct Answer
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A block slides across a rough horizontal table top.The work done by friction changes:

Correct Answer
verified

A stationary mass m = 1.3 kg is hanging from a spring of spring constant k = 1200 N/m.You raise the mass a distance of 10 cm above its equilibrium position in a time of 1.4 s.What was the average power expended?

Correct Answer
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The diagram shows a plot of the potential energy as a function of x for a particle moving along the x axis.The points of neutral equilibrium are:

Correct Answer
verified

A 6.0-kg block is released from rest 80 m above the ground.When it has fallen 60 m its kinetic energy is approximately:

Correct Answer
verified

A 0.50-kg block attached to an ideal spring with a spring constant of 80 N/m oscillates on a horizontal frictionless surface.The total mechanical energy is 0.12 J.The greatest extension of the spring from its equilibrium length is:

Correct Answer
verified

Correct Answer
verified

The potential energy of a 0.20-kg particle moving along the x axis is given by U(x) = (8.0 J/m²) x²− (2.0 J/m⁴) x⁴.When the particle is at x = 1.0 m the magnitude of its acceleration is:

Correct Answer
verified

A 700-N man jumps out of a window into a fire net 10 m below.The net stretches 2 m before bringing the man to rest and tossing him back into the air.The maximum potential energy of the net, compared to its unstretched potential energy, is:

Correct Answer
verified

The diagram shows a plot of the potential energy as a function of x for a particle moving along the x axis.The points of unstable equilibrium are:

Correct Answer
verified

A 2-kg block is thrown upward from a point 20 m above the Earth's surface.At what height above Earth's surface will the gravitational potential energy of the Earth-block system have increased by 500 J?

Correct Answer
verified

A good example of kinetic energy is provided by:

Correct Answer
verified

The sum of the kinetic and potential energies of a system of objects is conserved:

Correct Answer
verified

A 0.5-kg block slides along a horizontal frictionless surface at 2 m/s.It is brought to rest by compressing a very long spring of spring constant 800 N/m.The maximum spring compression is:

Correct Answer
verified

A stationary mass m = 1.3 kg is hanging from a spring of spring constant k = 1200 N/m.You raise the mass a distance of 10 cm above its equilibrium position.How much has the potential energy of the mass-spring system changed?

Correct Answer
verified

A golf ball is struck by a golf club and falls on a green eight feet above the tee.The potential energy of the Earth-ball system is greatest:

Correct Answer
verified

The thermal energy of a system consisting of a thrown ball, Earth, and the air is most closely associated with:

Correct Answer
verified

Exam 8: Potential Energy and Conservation of Energy

A small object of mass m, on the end of a light cord, is held horizontally at a distance r from a fixed support as shown.The object is then released.What is the tension in the cord when the object is at the lowest point of its swing?

Correct AnswerverifiedShow Answer

A ball is held at a height H above a floor.It is then released and falls to the floor.If air resistance can be ignored, which of the five graphs below correctly gives the mechanical energy E of the Earth-ball system as a function of the altitude y of the ball?

Correct AnswerverifiedShow Answer

No kinetic energy is possessed by:

Correct AnswerverifiedShow Answer

A nonconservative force:

Correct AnswerverifiedShow Answer

A block slides across a rough horizontal table top.The work done by friction changes:

Correct AnswerverifiedShow Answer

A stationary mass m = 1.3 kg is hanging from a spring of spring constant k = 1200 N/m.You raise the mass a distance of 10 cm above its equilibrium position in a time of 1.4 s.What was the average power expended?

Correct AnswerverifiedShow Answer

The diagram shows a plot of the potential energy as a function of x for a particle moving along the x axis.The points of neutral equilibrium are:

Correct AnswerverifiedShow Answer

A 6.0-kg block is released from rest 80 m above the ground.When it has fallen 60 m its kinetic energy is approximately:

Correct AnswerverifiedShow Answer

A 0.50-kg block attached to an ideal spring with a spring constant of 80 N/m oscillates on a horizontal frictionless surface.The total mechanical energy is 0.12 J.The greatest extension of the spring from its equilibrium length is:

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The potential energy of a 0.20-kg particle moving along the x axis is given by U(x) = (8.0 J/m2) x2 − (2.0 J/m4) x4.When the particle is at x = 1.0 m the magnitude of its acceleration is:

Correct AnswerverifiedShow Answer

A 700-N man jumps out of a window into a fire net 10 m below.The net stretches 2 m before bringing the man to rest and tossing him back into the air.The maximum potential energy of the net, compared to its unstretched potential energy, is:

Correct AnswerverifiedShow Answer

The diagram shows a plot of the potential energy as a function of x for a particle moving along the x axis.The points of unstable equilibrium are:

Correct AnswerverifiedShow Answer

A 2-kg block is thrown upward from a point 20 m above the Earth's surface.At what height above Earth's surface will the gravitational potential energy of the Earth-block system have increased by 500 J?

Correct AnswerverifiedShow Answer

A good example of kinetic energy is provided by:

Correct AnswerverifiedShow Answer

The sum of the kinetic and potential energies of a system of objects is conserved:

Correct AnswerverifiedShow Answer

A 0.5-kg block slides along a horizontal frictionless surface at 2 m/s.It is brought to rest by compressing a very long spring of spring constant 800 N/m.The maximum spring compression is:

Correct AnswerverifiedShow Answer

A stationary mass m = 1.3 kg is hanging from a spring of spring constant k = 1200 N/m.You raise the mass a distance of 10 cm above its equilibrium position.How much has the potential energy of the mass-spring system changed?

Correct AnswerverifiedShow Answer

A golf ball is struck by a golf club and falls on a green eight feet above the tee.The potential energy of the Earth-ball system is greatest:

Correct AnswerverifiedShow Answer

The thermal energy of a system consisting of a thrown ball, Earth, and the air is most closely associated with:

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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The potential energy of a 0.20-kg particle moving along the x axis is given by U(x) = (8.0 J/m²) x²− (2.0 J/m⁴) x⁴.When the particle is at x = 1.0 m the magnitude of its acceleration is:

Correct Answer
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Correct Answer
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