Question 1

The angular momentum of a flywheel about its axis is 925 kg · m2/s. If its moment of inertia about the same axis is 2.50 kg · m2, its angular velocity is

Accepted Answer

A)  370 rev/min 
B)  62 rev/min 
C)  36 rev/min 
D)  2210 rad/s 
E)  370 rad/s 
A)  370 rev/min 
B)  62 rev/min 
C)  36 rev/min 
D)  2210 rad/s 
E)  370 rad/s E

Question 2

The propeller of a motorboat turns clockwise relative to a water skier being towed by the boat. As the boat makes a sharp turn to the left, gyroscopic action tends to

Accepted Answer

A)  cause the front of the boat to rise. 
B)  cause the front of the boat to dip. 
C)  cause the boat to tip to the left. 
D)  cause the boat to tip to the right. 
E)  keep the boat headed in its original direction. 
A)  cause the front of the boat to rise. 
B)  cause the front of the boat to dip. 
C)  cause the boat to tip to the left. 
D)  cause the boat to tip to the right. 
E)  keep the boat headed in its original direction. A

Question 3

A certain airplane engine rotates counterclockwise when viewed from aft (that is, from the back of the airplane). When the plane turns to the left,

Accepted Answer

A)  the engine makes it turn faster than when it turns to the right. 
B)  the engine makes it turn slower than when it turns to the right. 
C)  it tends to dive. 
D)  it tends to climb. 
E)  the engine has no effect on the turn. 
A)  the engine makes it turn faster than when it turns to the right. 
B)  the engine makes it turn slower than when it turns to the right. 
C)  it tends to dive. 
D)  it tends to climb. 
E)  the engine has no effect on the turn. C

Question 4

A man is walking north carrying a suitcase that contains a spinning gyroscope mounted on an axle attached to the front and back of the case. The angular velocity of the gyroscope points north. The man now begins to turn to walk east. As a result, the front end of the suitcase

Accepted Answer

A)  resists his attempt to turn and tries to remain pointed north. 
B)  fights his attempt to turn and pulls to the west. 
C)  rises upward. 
D)  dips downward. 
E)  does nothing whatever unusual. 
A)  resists his attempt to turn and tries to remain pointed north. 
B)  fights his attempt to turn and pulls to the west. 
C)  rises upward. 
D)  dips downward. 
E)  does nothing whatever unusual.

Question 5

Which of the following are required for the total momentum (both angular and linear) of a system to be conserved?
1.The sum of the external torques acting on the system must be zero.
2.The sum of the external forces acting on the system must be zero.
3.The total kinetic energy must remain constant.
4.There can be no external torques or forces acting on the system.
5.There can be no internal torques or forces acting on the system.

Accepted Answer

A) 1 and 2 
B) 1, 2, and 3 
C) 1, 2, and 4 
D) 1, 2, 3, and 4 
E) 1, 2, 3, 4, and 5 
A) 1 and 2 
B) 1, 2, and 3 
C) 1, 2, and 4 
D) 1, 2, 3, and 4 
E) 1, 2, 3, 4, and 5

Question 6

Two identical cylindrical discs have a common axis. Initially one of the discs is spinning. When the two discs are brought into contact, they stick together. Which of the following is true?

Accepted Answer

A)  The total kinetic energy and the total angular momentum are unchanged from their initial values. 
B)  Both the total kinetic energy and the total angular momentum are reduced to half of their original values. 
C)  The total angular momentum is unchanged, but the total kinetic energy is reduced to half its original value. 
D)  The total angular momentum is reduced to half its original value, but the total kinetic energy is unchanged. 
E)  The total angular momentum is unchanged, and the total kinetic energy is reduced to one-quarter of its original value. 
A)  The total kinetic energy and the total angular momentum are unchanged from their initial values. 
B)  Both the total kinetic energy and the total angular momentum are reduced to half of their original values. 
C)  The total angular momentum is unchanged, but the total kinetic energy is reduced to half its original value. 
D)  The total angular momentum is reduced to half its original value, but the total kinetic energy is unchanged. 
E)  The total angular momentum is unchanged, and the total kinetic energy is reduced to one-quarter of its original value.

Question 7

Which of the following statements is true?

Accepted Answer

A)  Stable matter consists of electrons, protons, and neutrons. 
B)  Electrons, protons, and neutrons have an intrinsic angular momentum that is called spin. 
C)  Bosons have zero spin or integral spin. 
D)  The spin angular momentum of a particle is a fundamental property of the particle and as such cannot be changed. 
E)  All of these are correct. 
A)  Stable matter consists of electrons, protons, and neutrons. 
B)  Electrons, protons, and neutrons have an intrinsic angular momentum that is called spin. 
C)  Bosons have zero spin or integral spin. 
D)  The spin angular momentum of a particle is a fundamental property of the particle and as such cannot be changed. 
E)  All of these are correct.

Question 8

The angular momentum of a system is conserved only if

Accepted Answer

A)  the angular velocity is a function of time. 
B)  the sum of the external torques equals the sum of the internal torques. 
C)  the moment of inertia of the system is constant. 
D)  the sum of the external torques is zero. 
E)  the sum of the internal torques is zero. 
A)  the angular velocity is a function of time. 
B)  the sum of the external torques equals the sum of the internal torques. 
C)  the moment of inertia of the system is constant. 
D)  the sum of the external torques is zero. 
E)  the sum of the internal torques is zero.

Question 9

The angular momentum of a rotating object is initially   and 2s later it is   . The units are in kg.m2/s. The torque that produces the change in angular momentum is

Accepted Answer

A)    
B)    
C)    
D)    
E)  none of the above 
A)    
B)    
C)    
D)    
E)  none of the above

Question 10

As a particle with a velocity   in the negative x direction passes through the point (0, 0, 1), it has an angular velocity relative to the origin that is best represented by vector

Accepted Answer

A)    
B)    
C)    
D)    
E)  zero 
A)    
B)    
C)    
D)    
E)  zero

Question 11

A phonograph turntable in the xz plane is rotating clockwise as viewed from above. The vector that represents the torque with which the motor turns the table is

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 12

The angular momentum of a body about a particular axis as a function of time is shown in the graph. The external torque acting on the body along this axis at t = 2 s is

Accepted Answer

A)  0 
B)  5 N · m 
C)  10 N · m 
D)  20 N · m 
E)  40 N · m 
A)  0 
B)  5 N · m 
C)  10 N · m 
D)  20 N · m 
E)  40 N · m

Question 13

A 7-kg mass and a 4-kg mass are mounted on a spindle that is free to turn about the x axis as shown. Assume the mass of the arms and the spindle to be negligible. If the system is free to rotate and is released from rest, there will initially be a resultant torque in which of the following directions?

Accepted Answer

A)  z 
B)  -z 
C)  y 
D)  -x 
E)  x 
A)  z 
B)  -z 
C)  y 
D)  -x 
E)  x

Question 14

A wheel is rotating clockwise on a fixed axis perpendicular to the page (x). A torque that causes the wheel to slow down is best represented by the vector

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 15

A wheel is set spinning and then is hung by a rope placed at one end of the axle. The precession vector of the spinning wheel points in the direction of

Accepted Answer

A)  z 
B)  -y 
C)  -z 
D)  -x 
E)  y 
A)  z 
B)  -y 
C)  -z 
D)  -x 
E)  y

Question 16

A man stands on the center of a platform that is rotating on frictionless bearings at a speed of 1.00 rad/s. Originally his arms are outstretched and he holds a 4.54-kg mass in each hand. He then pulls the weights in toward his body. Assume the moment of inertia of the man, including his arms, to remain constant at 5.42 kg · m2. If the original distance of the weights from the axis is 0.914 m and their final distance is 0.305 m, the final angular velocity is

Accepted Answer

A)  1.14 rad/s 
B)  1.27 rad/s 
C)  1.58 rad/s 
D)  2.08 rad/s 
E)  7.70 rad/s 
A)  1.14 rad/s 
B)  1.27 rad/s 
C)  1.58 rad/s 
D)  2.08 rad/s 
E)  7.70 rad/s

Question 17

The vector   represents

Accepted Answer

A)    $\times$   
B)    ·   
C)    $\times$   
D)    $\times$   
E)  None of these is correct. 
A)    $\times$   
B)    ·   
C)    $\times$   
D)    $\times$   
E)  None of these is correct.

Question 18

A spinning bicycle wheel is supported as shown by a line fastened to one end of its axle. The resultant torque acting on the wheel lies along which of the following axes?

Accepted Answer

A)  x 
B)  y 
C)  -y 
D)  z 
E)  -z 
A)  x 
B)  y 
C)  -y 
D)  z 
E)  -z

Question 19

A merry-go-round with a moment of inertia of 6.78 $\times$ 103 kg · m2 is coasting at 2.20 rad/s. When a 72.6-kg man steps onto the rim, the angular velocity decreases to 2.0 rad/s. The radius of the merry-go-round is

Accepted Answer

A)  3.06 m 
B)  3.66 m 
C)  4.27 m 
D)  4.88 m 
E)  5.49 m 
A)  3.06 m 
B)  3.66 m 
C)  4.27 m 
D)  4.88 m 
E)  5.49 m

Question 20

In a rotating atomic nucleus shaped like a football the quantized energy levels have rotational quantum number values of 0, 2, 4, etc. If the energies of the first three states are 0 keV, 138 keV, and 460 keV, calculate the moment of inertia of the nucleus.

Accepted Answer

A)  9.41 $\times$10-36 keV•s2  
B)  9.41 $\times$ 10-36 eV•s2  
C)  1.43 $\times$ 10-17 keV•s2  
D)  1.43 $\times$ 10-17 eV•s2  
E)  9.41 $\times$ 10-33 keV•s2  
A)  9.41 $\times$10-36 keV•s2  
B)  9.41 $\times$ 10-36 eV•s2  
C)  1.43 $\times$ 10-17 keV•s2  
D)  1.43 $\times$ 10-17 eV•s2  
E)  9.41 $\times$ 10-33 keV•s2

The angular momentum of a flywheel about its axis is 925 kg · m²/s. If its moment of inertia about the same axis is 2.50 kg · m², its angular velocity is

The propeller of a motorboat turns clockwise relative to a water skier being towed by the boat. As the boat makes a sharp turn to the left, gyroscopic action tends to

A certain airplane engine rotates counterclockwise when viewed from aft (that is, from the back of the airplane). When the plane turns to the left,

A man is walking north carrying a suitcase that contains a spinning gyroscope mounted on an axle attached to the front and back of the case. The angular velocity of the gyroscope points north. The man now begins to turn to walk east. As a result, the front end of the suitcase

Two identical cylindrical discs have a common axis. Initially one of the discs is spinning. When the two discs are brought into contact, they stick together. Which of the following is true?

Which of the following statements is true?

The angular momentum of a system is conserved only if

The angular momentum of a rotating object is initially and 2s later it is . The units are in kg.m²/s. The torque that produces the change in angular momentum is

As a particle with a velocity in the negative x direction passes through the point (0, 0, 1), it has an angular velocity relative to the origin that is best represented by vector

A phonograph turntable in the xz plane is rotating clockwise as viewed from above. The vector that represents the torque with which the motor turns the table is

The angular momentum of a body about a particular axis as a function of time is shown in the graph. The external torque acting on the body along this axis at t = 2 s is

A wheel is rotating clockwise on a fixed axis perpendicular to the page (x). A torque that causes the wheel to slow down is best represented by the vector

A wheel is set spinning and then is hung by a rope placed at one end of the axle. The precession vector of the spinning wheel points in the direction of

The vector represents

A spinning bicycle wheel is supported as shown by a line fastened to one end of its axle. The resultant torque acting on the wheel lies along which of the following axes?

A merry-go-round with a moment of inertia of 6.78 $\times$ 10³ kg · m² is coasting at 2.20 rad/s. When a 72.6-kg man steps onto the rim, the angular velocity decreases to 2.0 rad/s. The radius of the merry-go-round is

In a rotating atomic nucleus shaped like a football the quantized energy levels have rotational quantum number values of 0, 2, 4, etc. If the energies of the first three states are 0 keV, 138 keV, and 460 keV, calculate the moment of inertia of the nucleus.

Systems of Measurement

Motion in One Dimension

Motion in Two and Three Dimensions

Newtons Laws

Applications of Newtons Laws

Work and Energy

Conservation of Energy

Systems of Particles and Conservation of Linear Momentum

Rotation

Gravity

Static Equilibrium and Elasticity

Fluids

Oscillations

Wave Motion

Superposition and Standing Waves

Temperature and the Kinetic Theory of Gases

Heat and the First Law of Thermodynamics

The Second Law of Thermodynamics

Thermal Properties and Processes

Filters

Exam 10: Conservation of Angular Momentum

The angular momentum of a flywheel about its axis is 925 kg · m2/s. If its moment of inertia about the same axis is 2.50 kg · m2, its angular velocity is

The propeller of a motorboat turns clockwise relative to a water skier being towed by the boat. As the boat makes a sharp turn to the left, gyroscopic action tends to

A certain airplane engine rotates counterclockwise when viewed from aft (that is, from the back of the airplane). When the plane turns to the left,

A man is walking north carrying a suitcase that contains a spinning gyroscope mounted on an axle attached to the front and back of the case. The angular velocity of the gyroscope points north. The man now begins to turn to walk east. As a result, the front end of the suitcase

Two identical cylindrical discs have a common axis. Initially one of the discs is spinning. When the two discs are brought into contact, they stick together. Which of the following is true?

Which of the following statements is true?

The angular momentum of a system is conserved only if

The angular momentum of a rotating object is initially and 2s later it is . The units are in kg.m2/s. The torque that produces the change in angular momentum is

As a particle with a velocity in the negative x direction passes through the point (0, 0, 1), it has an angular velocity relative to the origin that is best represented by vector

A phonograph turntable in the xz plane is rotating clockwise as viewed from above. The vector that represents the torque with which the motor turns the table is

The angular momentum of a body about a particular axis as a function of time is shown in the graph. The external torque acting on the body along this axis at t = 2 s is

A wheel is rotating clockwise on a fixed axis perpendicular to the page (x). A torque that causes the wheel to slow down is best represented by the vector

A wheel is set spinning and then is hung by a rope placed at one end of the axle. The precession vector of the spinning wheel points in the direction of

The vector represents

A spinning bicycle wheel is supported as shown by a line fastened to one end of its axle. The resultant torque acting on the wheel lies along which of the following axes?

A merry-go-round with a moment of inertia of 6.78 ×\times× 103 kg · m2 is coasting at 2.20 rad/s. When a 72.6-kg man steps onto the rim, the angular velocity decreases to 2.0 rad/s. The radius of the merry-go-round is

In a rotating atomic nucleus shaped like a football the quantized energy levels have rotational quantum number values of 0, 2, 4, etc. If the energies of the first three states are 0 keV, 138 keV, and 460 keV, calculate the moment of inertia of the nucleus.

Systems of Measurement

Motion in One Dimension

Motion in Two and Three Dimensions

Newtons Laws

Applications of Newtons Laws

Work and Energy

Conservation of Energy

Systems of Particles and Conservation of Linear Momentum

Rotation

Gravity

Static Equilibrium and Elasticity

Fluids

Oscillations

Wave Motion

Superposition and Standing Waves

Temperature and the Kinetic Theory of Gases

Heat and the First Law of Thermodynamics

The Second Law of Thermodynamics

Thermal Properties and Processes

Filters

The angular momentum of a flywheel about its axis is 925 kg · m²/s. If its moment of inertia about the same axis is 2.50 kg · m², its angular velocity is

The angular momentum of a rotating object is initially and 2s later it is . The units are in kg.m²/s. The torque that produces the change in angular momentum is

A merry-go-round with a moment of inertia of 6.78 $\times$ 10³ kg · m² is coasting at 2.20 rad/s. When a 72.6-kg man steps onto the rim, the angular velocity decreases to 2.0 rad/s. The radius of the merry-go-round is