Question 1

If there is a net torque on a wheel, then

Accepted Answer

A)  there must be a net force on the wheel. 
B)  the wheel must have a nonzero angular acceleration. 
C)  the wheel cannot be spinning. 
D)  the angular momentum of the wheel cannot change direction. 
A)  there must be a net force on the wheel. 
B)  the wheel must have a nonzero angular acceleration. 
C)  the wheel cannot be spinning. 
D)  the angular momentum of the wheel cannot change direction. B

Question 2

If the net force on a body is zero, the net torque on the body is

Accepted Answer

A)  always zero. 
B)  not necessarily zero. 
C)  certainly not zero. 
A)  always zero. 
B)  not necessarily zero. 
C)  certainly not zero. B

Question 3

Using a longer-handled wrench to loosen a tight nut allows you to

Accepted Answer

A)  exert more force on the nut. 
B)  apply more torque to the nut. 
C)  increase the moment of inertia of the nut. 
D)  pull harder on the wrench. 
A)  exert more force on the nut. 
B)  apply more torque to the nut. 
C)  increase the moment of inertia of the nut. 
D)  pull harder on the wrench. B

Question 4

Which of the following is an appropriate unit for describing rotational acceleration?

Accepted Answer

A)  m/s2 
B)  rad/min 
C)  rev/min 
D)  rev/m/s 
E)  rev/min2 
A)  m/s2 
B)  rad/min 
C)  rev/min 
D)  rev/m/s 
E)  rev/min2

Question 5

A spinning wheel has an angular momentum that points toward the east. If an eastward force is applied to the edge of the wheel,

Accepted Answer

A)  the angular momentum of the wheel will change direction but not magnitude. 
B)  the angular momentum will get larger. 
C)  the angular momentum will get smaller. 
D)  the angular momentum of the wheel will not change. 
A)  the angular momentum of the wheel will change direction but not magnitude. 
B)  the angular momentum will get larger. 
C)  the angular momentum will get smaller. 
D)  the angular momentum of the wheel will not change.

Question 6

A dancer begins performing a pirouette with arms extended. (A pirouette is a complete spin about a vertical axis.) This motion is completed most easily when the rotational inertia is decreased by

Accepted Answer

A)  bending at the waist at a right angle. 
B)  extending the arms and one leg straight out to the sides. 
C)  holding the arms straight up and extending one foot straight out to the side. 
D)  bringing the arms and legs in a line with the body. 
A)  bending at the waist at a right angle. 
B)  extending the arms and one leg straight out to the sides. 
C)  holding the arms straight up and extending one foot straight out to the side. 
D)  bringing the arms and legs in a line with the body.

Question 7

The angular momentum of an isolated object can be changed only by

Accepted Answer

A)  changing its rotational inertia. 
B)  applying a torque. 
C)  applying a force along the axis of rotation. 
A)  changing its rotational inertia. 
B)  applying a torque. 
C)  applying a force along the axis of rotation.

Question 8

A torque acting on a body tends to produce

Accepted Answer

A)  equilibrium. 
B)  linear velocity. 
C)  a new center of gravity. 
D)  angular rotation. 
A)  equilibrium. 
B)  linear velocity. 
C)  a new center of gravity. 
D)  angular rotation.

Question 9

If you push directly on the handle of a closed door and it does not swing open, then

Accepted Answer

A)  its rotational inertia must be much larger than your torque. 
B)  the net torque on the door must be zero. 
C)  the lever arm must be very small. 
D)  the angular momentum of the door is larger than your force. 
A)  its rotational inertia must be much larger than your torque. 
B)  the net torque on the door must be zero. 
C)  the lever arm must be very small. 
D)  the angular momentum of the door is larger than your force.

Question 10

When a mechanic uses an extension arm on his wrench to loosen a stubborn nut, he is exerting additional torque because of an increase in the _________________ (two words) of the force.

Accepted Answer

The answer of When a mechanic uses an extension arm...

Question 11

If the net torque on a body is zero, the net force on the body is

Accepted Answer

A)  always zero. 
B)  not necessarily zero. 
C)  certainly not zero. 
A)  always zero. 
B)  not necessarily zero. 
C)  certainly not zero.

Question 12

A merry-go-round is set into motion with a child on board. The rotational speed of the merry-go-round _____________ as the child moves inward along a radius.

Accepted Answer

The answer of A merry-go-round is set into motion with...

Question 13

The advantage that a lever can give you is that

Accepted Answer

A)  with a small force, you can move a large weight. 
B)  with a small lever, you can move a large weight. 
C)  with a large force, you can torque a large weight. 
D)  with a small torque, you can lift a large weight. 
A)  with a small force, you can move a large weight. 
B)  with a small lever, you can move a large weight. 
C)  with a large force, you can torque a large weight. 
D)  with a small torque, you can lift a large weight.

Question 14

A student plays on a see-saw with her experimental android robot, Robby. The student has a weight of 300 N and is seated 2.8 m from the axis of rotation. Robby balances her when he is seated 0.7 m from the axis. Robby's weight is

Accepted Answer

A)  1000 N. 
B)  500 N. 
C)  667 N. 
D)  725 N. 
E)  1200 N. 
A)  1000 N. 
B)  500 N. 
C)  667 N. 
D)  725 N. 
E)  1200 N.

Question 15

A flywheel is used to minimize changes in rotational velocity as the torque or the load changes. The rotational inertia of a flywheel should be chosen to be

Accepted Answer

A)  anything-it doesn't matter. 
B)  as small as possible. 
C)  as large as possible. 
A)  anything-it doesn't matter. 
B)  as small as possible. 
C)  as large as possible.

Question 16

A solid disk and a hollow disk with the same mass and diameter are released together (from rest) to roll down an incline. The solid disk reaches the bottom first. From this information we can say that the angular acceleration was

Accepted Answer

A)  larger for the hollow disk. 
B)  larger for the solid disk. 
C)  the same for both disks. 
D)  impossible to know without a measurement of time. 
A)  larger for the hollow disk. 
B)  larger for the solid disk. 
C)  the same for both disks. 
D)  impossible to know without a measurement of time.

Question 17

A gyroscope consists of a wheel mounted on an axle aligned along a north-south direction. The south end of the axle is suspended by a rope attached to the ceiling, and the north end is manually held at rest. The wheel is spinning rapidly, so that its angular momentum vector points north. Suddenly the north end is released. Since there is spin, the north end of the axle will begin to move

Accepted Answer

A)  north. 
B)  east. 
C)  down. 
D)  west. 
E)  south. 
A)  north. 
B)  east. 
C)  down. 
D)  west. 
E)  south.

Question 18

When a bicycle pedal is at the top of its motion, you can exert the greatest torque on the crank by

Accepted Answer

A)  pushing straight down on the pedal with your foot. 
B)  hooking your toes under the pedal and pulling upward. 
C)  pushing straight forward on the pedal with your foot. 
A)  pushing straight down on the pedal with your foot. 
B)  hooking your toes under the pedal and pulling upward. 
C)  pushing straight forward on the pedal with your foot.

Question 19

When an ice skater twirling on the point of a skate draws her arms in she ends up whirling faster. This is because

Accepted Answer

A)  rotational energy is conserved. 
B)  linear momentum is conserved. 
C)  angular momentum is conserved. 
D)  a net external torque acts on the skater. 
A)  rotational energy is conserved. 
B)  linear momentum is conserved. 
C)  angular momentum is conserved. 
D)  a net external torque acts on the skater.

Question 20

The armature (or spinning portion) of a motor is accelerated uniformly from rest to a rotational velocity of 1500 rev/min in 10 seconds. The rotational acceleration of the motor is

Accepted Answer

A)  150 rad/s2. 
B)  15.7 rad/s2. 
C)  31.4 rad/s2. 
D)  75 rad/s2. 
E)  zero. 
A)  150 rad/s2. 
B)  15.7 rad/s2. 
C)  31.4 rad/s2. 
D)  75 rad/s2. 
E)  zero.

If there is a net torque on a wheel, then

If the net force on a body is zero, the net torque on the body is

Using a longer-handled wrench to loosen a tight nut allows you to

Which of the following is an appropriate unit for describing rotational acceleration?

A spinning wheel has an angular momentum that points toward the east. If an eastward force is applied to the edge of the wheel,

A dancer begins performing a pirouette with arms extended. (A pirouette is a complete spin about a vertical axis.) This motion is completed most easily when the rotational inertia is decreased by

The angular momentum of an isolated object can be changed only by

A torque acting on a body tends to produce

If you push directly on the handle of a closed door and it does not swing open, then

When a mechanic uses an extension arm on his wrench to loosen a stubborn nut, he is exerting additional torque because of an increase in the _________________ (two words) of the force.

If the net torque on a body is zero, the net force on the body is

A merry-go-round is set into motion with a child on board. The rotational speed of the merry-go-round _____________ as the child moves inward along a radius.

The advantage that a lever can give you is that

A student plays on a see-saw with her experimental android robot, Robby. The student has a weight of 300 N and is seated 2.8 m from the axis of rotation. Robby balances her when he is seated 0.7 m from the axis. Robby's weight is

A flywheel is used to minimize changes in rotational velocity as the torque or the load changes. The rotational inertia of a flywheel should be chosen to be

A solid disk and a hollow disk with the same mass and diameter are released together (from rest) to roll down an incline. The solid disk reaches the bottom first. From this information we can say that the angular acceleration was

When a bicycle pedal is at the top of its motion, you can exert the greatest torque on the crank by

When an ice skater twirling on the point of a skate draws her arms in she ends up whirling faster. This is because

The armature (or spinning portion) of a motor is accelerated uniformly from rest to a rotational velocity of 1500 rev/min in 10 seconds. The rotational acceleration of the motor is

Physics, the Fundamental Science

Describing Motion

Falling Objects and Projectile Motion

Newtons Laws: Explaining Motion

Circular Motion, the Planets, and Gravity

Energy and Oscillations

Momentum and Impulse

The Behavior of Fluids

Temperature and Heat

Heat Engines and the Second Law of Thermodynamics

Electrostatic Phenomena

Electric Circuits

Magnets and Electromagnetism

Making Waves

Light Waves and Color

Light and Image Formation

The Structure of the Atom

The Nucleus and Nuclear Energy

Relativity

Beyond Everyday Phenomena

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Exam 8: Rotational Motion of Solid Objects

If there is a net torque on a wheel, then

If the net force on a body is zero, the net torque on the body is

Using a longer-handled wrench to loosen a tight nut allows you to

Which of the following is an appropriate unit for describing rotational acceleration?

A spinning wheel has an angular momentum that points toward the east. If an eastward force is applied to the edge of the wheel,

A dancer begins performing a pirouette with arms extended. (A pirouette is a complete spin about a vertical axis.) This motion is completed most easily when the rotational inertia is decreased by

The angular momentum of an isolated object can be changed only by

A torque acting on a body tends to produce

If you push directly on the handle of a closed door and it does not swing open, then

When a mechanic uses an extension arm on his wrench to loosen a stubborn nut, he is exerting additional torque because of an increase in the _________________ (two words) of the force.

If the net torque on a body is zero, the net force on the body is

A merry-go-round is set into motion with a child on board. The rotational speed of the merry-go-round _____________ as the child moves inward along a radius.

The advantage that a lever can give you is that

A student plays on a see-saw with her experimental android robot, Robby. The student has a weight of 300 N and is seated 2.8 m from the axis of rotation. Robby balances her when he is seated 0.7 m from the axis. Robby's weight is

A flywheel is used to minimize changes in rotational velocity as the torque or the load changes. The rotational inertia of a flywheel should be chosen to be

A solid disk and a hollow disk with the same mass and diameter are released together (from rest) to roll down an incline. The solid disk reaches the bottom first. From this information we can say that the angular acceleration was

When a bicycle pedal is at the top of its motion, you can exert the greatest torque on the crank by

When an ice skater twirling on the point of a skate draws her arms in she ends up whirling faster. This is because

The armature (or spinning portion) of a motor is accelerated uniformly from rest to a rotational velocity of 1500 rev/min in 10 seconds. The rotational acceleration of the motor is

Physics, the Fundamental Science

Describing Motion

Falling Objects and Projectile Motion

Newtons Laws: Explaining Motion

Circular Motion, the Planets, and Gravity

Energy and Oscillations

Momentum and Impulse

The Behavior of Fluids

Temperature and Heat

Heat Engines and the Second Law of Thermodynamics

Electrostatic Phenomena

Electric Circuits

Magnets and Electromagnetism

Making Waves

Light Waves and Color

Light and Image Formation

The Structure of the Atom

The Nucleus and Nuclear Energy

Relativity

Beyond Everyday Phenomena

Filters