Question 1

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 battery 
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 battery

Question 2

For a block of mass m to slide without friction up the rise of height h shown, it must have a minimum initial kinetic energy of:

Accepted Answer

A) gh 
B) mgh 
C) gh/2 
D) mgh/2 
E) 2mgh 
A) gh 
B) mgh 
C) gh/2 
D) mgh/2 
E) 2mgh

Question 3

The energy of a system increases at a rate of 3.5 t + 6.2 t2, in joules.What is the instantaneous power at t = 3.1 s?

Accepted Answer

A) 3.5 W 
B) 6.2 W 
C) 16 W 
D) 42 W 
E) 70 W 
A) 3.5 W 
B) 6.2 W 
C) 16 W 
D) 42 W 
E) 70 W

Question 4

A simple pendulum consists of a 2.0 kg mass attached to a string.It is released from rest at X as shown.Its speed at the lowest point Y is:

Accepted Answer

A) 1.9 m/s 
B) 3.7 m/s 
C) 4.4 m/s 
D) 6.0 m/s 
E) 36 m/s 
A) 1.9 m/s 
B) 3.7 m/s 
C) 4.4 m/s 
D) 6.0 m/s 
E) 36 m/s

Question 5

A 0.75-kg block slides on a rough horizontal table top.Just before it hits a horizontal ideal spring its speed is 3.5 m/s.It compresses the spring 5.7 cm before coming to rest.If the spring constant is 1200 N/m, the thermal energy of the block and the table top must have:

Accepted Answer

A) not changed 
B) decreased by 1.9 J 
C) decreased by 2.6 J 
D) increased by 1.9 J 
E) increased by 2.6 J 
A) not changed 
B) decreased by 1.9 J 
C) decreased by 2.6 J 
D) increased by 1.9 J 
E) increased by 2.6 J

Question 6

Only if a force on a particle is conservative:

Accepted Answer

A) does it do no work when the particle moves exactly once around any closed path 
B) does the work it does equal the change in the kinetic energy of the particle 
C) does it obey Newton's second law 
D) does it obey Newton's third law 
E) it is not a frictional force 
A) does it do no work when the particle moves exactly once around any closed path 
B) does the work it does equal the change in the kinetic energy of the particle 
C) does it obey Newton's second law 
D) does it obey Newton's third law 
E) it is not a frictional force

Question 7

A 0.20-kg particle moves along the x axis under the influence of a conservative force.The potential energy is given by U(x)= (8.0 J/m2)x2 + (2.0 J/m4)x4,
Where x is in coordinate of the particle.If the particle has a speed of 5.0 m/s when it is at x = 1.0 m, its speed when it is at the origin is:

Accepted Answer

A) 0 m/s 
B) 2.5 m/s 
C) 5.7 m/s 
D) 7.9 m/s 
E) 11 m/s 
A) 0 m/s 
B) 2.5 m/s 
C) 5.7 m/s 
D) 7.9 m/s 
E) 11 m/s

Question 8

A 5-kg projectile is fired over level ground with a velocity of 200 m/s at an angle of 25$\degree$ above the horizontal.Just before it hits the ground its speed is 150 m/s.Over the entire trip the change in the thermal energy of the projectile and air is:

Accepted Answer

A) +6300 J 
B) -6300 J 
C) +44,000 J 
D) -44,000 J 
E) 0 J 
A) +6300 J 
B) -6300 J 
C) +44,000 J 
D) -44,000 J 
E) 0 J

Question 9

The potential energy for the interaction between the two atoms in a diatomic molecule is U = A/x12 - B/x6, where A and B are constants and x is the interatomic distance.The magnitude of the force that one atom exerts on the other is:

Accepted Answer

A) 12A/x13 - 6B/x7 
B) -13A/x13 + 7B/x7 
C) -11A/x11 + 5B/x5 
D) 72A/x12 - 72B/x6 
E) A/x13 - B/x7 
A) 12A/x13 - 6B/x7 
B) -13A/x13 + 7B/x7 
C) -11A/x11 + 5B/x5 
D) 72A/x12 - 72B/x6 
E) A/x13 - B/x7

Question 10

A rectangular block is moving along a frictionless path when it encounters the circular loop as shown.The block passes points 1,2,3,4,1 before returning to the horizontal track.At point 3:

Accepted Answer

A) its mechanical energy is a minimum 
B) the forces on it are balanced 
C) it is not accelerating 
D) its speed is a minimum 
E) it experiences a net upward force 
A) its mechanical energy is a minimum 
B) the forces on it are balanced 
C) it is not accelerating 
D) its speed is a minimum 
E) it experiences a net upward force

Question 11

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 energies 
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 energies

Question 12

A toy cork gun contains a spring whose spring constant is 10.0 N/m.The spring is compressed 5.00 cm and then used to propel a 6.00-g cork.The cork, however, sticks to the spring for 1.00 cm beyond its unstretched length before separation occurs.The muzzle velocity of this cork is:

Accepted Answer

A) 1.02 m/s 
B) 1.41 m/s 
C) 2.00 m/s 
D) 2.04 m/s 
E) 4.00 m/s 
A) 1.02 m/s 
B) 1.41 m/s 
C) 2.00 m/s 
D) 2.04 m/s 
E) 4.00 m/s

Question 13

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 speed of the block is:

Accepted Answer

A) 0.15 m/s 
B) 0.24 m/s 
C) 0.49 m/s 
D) 0.69 m/s 
E) 1.46 m/s 
A) 0.15 m/s 
B) 0.24 m/s 
C) 0.49 m/s 
D) 0.69 m/s 
E) 1.46 m/s

Question 14

A 25-g ball is released from rest 80 m above the surface of the Earth.During the fall the total thermal energy of the ball and air increases by15 J.Just before it hits the surface its speed is

Accepted Answer

A) 19 m/s 
B) 35 m/s 
C) 40 m/s 
D) 45 m/s 
E) 53 m/s 
A) 19 m/s 
B) 35 m/s 
C) 40 m/s 
D) 45 m/s 
E) 53 m/s

Question 15

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 whole 
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 whole

Question 16

In this graph of potential energy vs.x, the horizontal line represents the total mechanical energy of a particle.Approximately what is its kinetic energy at x = 15 m?

Accepted Answer

A) 5 J 
B) 10 J 
C) 15 J 
D) 20 J 
E) 25 J 
A) 5 J 
B) 10 J 
C) 15 J 
D) 20 J 
E) 25 J

Question 17

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 m 
A) 1.5 * 10-3 m 
B) 3.0 * 10-3 m 
C) 0.039 m 
D) 0.055 m 
E) 18 m

Question 18

A small object of mass m starts at rest at the position shown and slides along the frictionless loop-the-loop track of radius R.What is the smallest value of y such that the object will slide without losing contact with the track?

Accepted Answer

A) R/4 
B) R/2 
C) R 
D) 2R 
E) 0 
A) R/4 
B) R/2 
C) R 
D) 2R 
E) 0

Question 19

The first graph shows the potential energy U(x)for a particle moving on the x axis.Which of the following five graphs correctly gives the force F exerted on the particle?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 20

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) mgr 
A) mg/2 
B) mg 
C) 2 mg 
D) 3 mg 
E) mgr

Exam 8: Potential Energy and Conservation of Energy

A good example of kinetic energy is provided by:

For a block of mass m to slide without friction up the rise of height h shown, it must have a minimum initial kinetic energy of:

The energy of a system increases at a rate of 3.5 t + 6.2 t2, in joules.What is the instantaneous power at t = 3.1 s?

A simple pendulum consists of a 2.0 kg mass attached to a string.It is released from rest at X as shown.Its speed at the lowest point Y is:

A 0.75-kg block slides on a rough horizontal table top.Just before it hits a horizontal ideal spring its speed is 3.5 m/s.It compresses the spring 5.7 cm before coming to rest.If the spring constant is 1200 N/m, the thermal energy of the block and the table top must have:

Only if a force on a particle is conservative:

A 0.20-kg particle moves along the x axis under the influence of a conservative force.The potential energy is given by U(x)= (8.0 J/m2)x2 + (2.0 J/m4)x4, Where x is in coordinate of the particle.If the particle has a speed of 5.0 m/s when it is at x = 1.0 m, its speed when it is at the origin is:

A 5-kg projectile is fired over level ground with a velocity of 200 m/s at an angle of 25 °\degree° above the horizontal.Just before it hits the ground its speed is 150 m/s.Over the entire trip the change in the thermal energy of the projectile and air is:

The potential energy for the interaction between the two atoms in a diatomic molecule is U = A/x12 - B/x6, where A and B are constants and x is the interatomic distance.The magnitude of the force that one atom exerts on the other is:

A rectangular block is moving along a frictionless path when it encounters the circular loop as shown.The block passes points 1,2,3,4,1 before returning to the horizontal track.At point 3:

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

A toy cork gun contains a spring whose spring constant is 10.0 N/m.The spring is compressed 5.00 cm and then used to propel a 6.00-g cork.The cork, however, sticks to the spring for 1.00 cm beyond its unstretched length before separation occurs.The muzzle velocity of this cork is:

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 speed of the block is:

A 25-g ball is released from rest 80 m above the surface of the Earth.During the fall the total thermal energy of the ball and air increases by15 J.Just before it hits the surface its speed is

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

In this graph of potential energy vs.x, the horizontal line represents the total mechanical energy of a particle.Approximately what is its kinetic energy at x = 15 m?

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:

A small object of mass m starts at rest at the position shown and slides along the frictionless loop-the-loop track of radius R.What is the smallest value of y such that the object will slide without losing contact with the track?

The first graph shows the potential energy U(x)for a particle moving on the x axis.Which of the following five graphs correctly gives the force F exerted on the particle?

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?

Measurement

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Vector

Motion in Two and Three Dimensions

Force and Motion I

Force and Motion II

Kinetic Energy and Work

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

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Photons and Matter Waves

More About Matter Waves

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Energy From the Nucleus

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Filters

The energy of a system increases at a rate of 3.5 t + 6.2 t², in joules.What is the instantaneous power at t = 3.1 s?

A 5-kg projectile is fired over level ground with a velocity of 200 m/s at an angle of 25 $\degree$ above the horizontal.Just before it hits the ground its speed is 150 m/s.Over the entire trip the change in the thermal energy of the projectile and air is:

The potential energy for the interaction between the two atoms in a diatomic molecule is U = A/x¹² - B/x⁶, where A and B are constants and x is the interatomic distance.The magnitude of the force that one atom exerts on the other is: