Question 1

The bigger diameter gears on the rear wheel of a multi-speed bike allow the rider to

Accepted Answer

A)  increase the moment of inertia of the wheel. 
B)  exert more force on the wheel. 
C)  exert more torque on the wheel. 
D)  decrease the moment of inertia of the wheel. 
A)  increase the moment of inertia of the wheel. 
B)  exert more force on the wheel. 
C)  exert more torque on the wheel. 
D)  decrease the moment of inertia of the wheel.

Question 2

A hoop and a sphere have the same diameter and the same mass. Which one will have a larger rotational inertia?

Accepted Answer

A)  The hoop. 
B)  The sphere. 
C)  Both will require the same time to reach the bottom. 
A)  The hoop. 
B)  The sphere. 
C)  Both will require the same time to reach the bottom.

Question 3

A constant torque is applied to a flywheel. Which of the following mechanical quantities will be constant?

Accepted Answer

A)  Rotational energy 
B)  Angular momentum 
C)  Rotational velocity 
D)  Rotational acceleration 
E)  Linear velocity of a particle on the rim 
A)  Rotational energy 
B)  Angular momentum 
C)  Rotational velocity 
D)  Rotational acceleration 
E)  Linear velocity of a particle on the rim

Question 4

Just as torque is the rotational analogue of force in linear motion, rotational inertia is the rotational analogue of _______ in linear motion.

Accepted Answer

The answer of Just as torque is the rotational analogue...

Question 5

An isolated object is initially spinning at a constant speed. Then, although no external forces act upon it, its rotational speed increases. This must be due to

Accepted Answer

A)  an increase in the moment of inertia. 
B)  an increase in the mass. 
C)  an increase in the angular momentum. 
D)  a decrease in the moment of inertia. 
E)  impossible, angular momentum conservation is violated. 
A)  an increase in the moment of inertia. 
B)  an increase in the mass. 
C)  an increase in the angular momentum. 
D)  a decrease in the moment of inertia. 
E)  impossible, angular momentum conservation is violated.

Question 6

The angular momentum of a rotating body is constant when the net _______________ on the body is zero.

Accepted Answer

The answer of The angular momentum of a rotating body...

Question 7

You stand with your heels against a wall and bend ninety degrees forward at the waist.

Accepted Answer

A)  You fall forward because your center of gravity moves ahead of your base of support. 
B)  You fall forward because of the momentum you gain when you move. 
C)  You are able to maintain your balance. 
D)  You fall forward because the muscles in your feet aren't strong enough to stop you. 
A)  You fall forward because your center of gravity moves ahead of your base of support. 
B)  You fall forward because of the momentum you gain when you move. 
C)  You are able to maintain your balance. 
D)  You fall forward because the muscles in your feet aren't strong enough to stop you.

Question 8

A merry-go-round, having a radius of 2.5 m, is set in motion starting from rest, by students applying a force of 500 N tangential to the rim of the wheel. After five seconds of torque, the students let go and measure the rotational speed: 1.25 rad/s. The rotational inertia of the merry-go-round is

Accepted Answer

A)  7.5 $\times$ 102 kg m2. 
B)  1.7 $\times$ 103 kg m2. 
C)  2.5 $\times$ 103 kg m2. 
D)  5.0 $\times$ 103 kg m2. 
E)  1.0 $\times$ 104 kg m2. 
A)  7.5 $\times$ 102 kg m2. 
B)  1.7 $\times$ 103 kg m2. 
C)  2.5 $\times$ 103 kg m2. 
D)  5.0 $\times$ 103 kg m2. 
E)  1.0 $\times$ 104 kg m2.

Question 9

A moving bicycle exhibits less stability when the angular momentum of the wheels is less, which means

Accepted Answer

A)  its forward speed is also slower. 
B)  its forward speed is faster. 
C)  the inverse of the forward speed equals the torque. 
A)  its forward speed is also slower. 
B)  its forward speed is faster. 
C)  the inverse of the forward speed equals the torque.

Question 10

A figure skater is spinning with her arms extended. She now pulls her arms close to her body. What happens?

Accepted Answer

A)  Her angular acceleration decreases. 
B)  Her rotational inertia decreases. 
C)  The net external torque on her increases. 
D)  Her lever arm gets shorter. 
A)  Her angular acceleration decreases. 
B)  Her rotational inertia decreases. 
C)  The net external torque on her increases. 
D)  Her lever arm gets shorter.

Question 11

Three horses are side-by-side on a merry-go-round: one at the edge, one near the axis, and one in between. Each horse has the same angular speed. Which horse has the greatest linear speed?

Accepted Answer

A)  The horse at the edge. 
B)  The horse in the middle. 
C)  The horse nearest the axis. 
D)  The linear speed is the same for all three horses. 
A)  The horse at the edge. 
B)  The horse in the middle. 
C)  The horse nearest the axis. 
D)  The linear speed is the same for all three horses.

Question 12

Three different bodies-a uniform sphere, a uniform disk, and a hoop-all have same radius and same mass. The body with the largest rotational inertia will be

Accepted Answer

A)  the sphere. 
B)  the disk. 
C)  the hoop. 
D)  none, as all have the same value of rotational inertia. 
A)  the sphere. 
B)  the disk. 
C)  the hoop. 
D)  none, as all have the same value of rotational inertia.

Question 13

It is possible using the analogies between linear motion and rotational motion to write an expression for rotational kinetic energy. The formula for rotational kinetic energy (assuming $ \tau $ is torque, $\alpha$ is angular acceleration, I is rotational inertia, and $ \omega $ is angular velocity) is

Accepted Answer

A)  ½ $ \tau $ $\alpha$2. 
B)  ½ I $\alpha$2. 
C)  ½ I $ \omega $2. 
D)  ½ $ \tau $ $ \omega $2.
  
A)  ½ $ \tau $ $\alpha$2. 
B)  ½ I $\alpha$2. 
C)  ½ I $ \omega $2. 
D)  ½ $ \tau $ $ \omega $2.

Question 14

In a stable stack of identical boards at the edge of a table, the center of gravity of the top board

Accepted Answer

A)  must lie above the table. 
B)  need not lie over anything. 
C)  must lie above the bottom board. 
D)  must lie above the next lower board. 
A)  must lie above the table. 
B)  need not lie over anything. 
C)  must lie above the bottom board. 
D)  must lie above the next lower board.

The bigger diameter gears on the rear wheel of a multi-speed bike allow the rider to

A hoop and a sphere have the same diameter and the same mass. Which one will have a larger rotational inertia?

A constant torque is applied to a flywheel. Which of the following mechanical quantities will be constant?

Just as torque is the rotational analogue of force in linear motion, rotational inertia is the rotational analogue of _______ in linear motion.

An isolated object is initially spinning at a constant speed. Then, although no external forces act upon it, its rotational speed increases. This must be due to

The angular momentum of a rotating body is constant when the net _______________ on the body is zero.

You stand with your heels against a wall and bend ninety degrees forward at the waist.

A merry-go-round, having a radius of 2.5 m, is set in motion starting from rest, by students applying a force of 500 N tangential to the rim of the wheel. After five seconds of torque, the students let go and measure the rotational speed: 1.25 rad/s. The rotational inertia of the merry-go-round is

A moving bicycle exhibits less stability when the angular momentum of the wheels is less, which means

A figure skater is spinning with her arms extended. She now pulls her arms close to her body. What happens?

Three horses are side-by-side on a merry-go-round: one at the edge, one near the axis, and one in between. Each horse has the same angular speed. Which horse has the greatest linear speed?

Three different bodies-a uniform sphere, a uniform disk, and a hoop-all have same radius and same mass. The body with the largest rotational inertia will be

It is possible using the analogies between linear motion and rotational motion to write an expression for rotational kinetic energy. The formula for rotational kinetic energy (assuming $\tau$ is torque, $\alpha$ is angular acceleration, I is rotational inertia, and $\omega$ is angular velocity) is

In a stable stack of identical boards at the edge of a table, the center of gravity of the top board

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

The bigger diameter gears on the rear wheel of a multi-speed bike allow the rider to

A hoop and a sphere have the same diameter and the same mass. Which one will have a larger rotational inertia?

A constant torque is applied to a flywheel. Which of the following mechanical quantities will be constant?

Just as torque is the rotational analogue of force in linear motion, rotational inertia is the rotational analogue of _______ in linear motion.

An isolated object is initially spinning at a constant speed. Then, although no external forces act upon it, its rotational speed increases. This must be due to

The angular momentum of a rotating body is constant when the net _______________ on the body is zero.

You stand with your heels against a wall and bend ninety degrees forward at the waist.

A merry-go-round, having a radius of 2.5 m, is set in motion starting from rest, by students applying a force of 500 N tangential to the rim of the wheel. After five seconds of torque, the students let go and measure the rotational speed: 1.25 rad/s. The rotational inertia of the merry-go-round is

A moving bicycle exhibits less stability when the angular momentum of the wheels is less, which means

A figure skater is spinning with her arms extended. She now pulls her arms close to her body. What happens?

Three horses are side-by-side on a merry-go-round: one at the edge, one near the axis, and one in between. Each horse has the same angular speed. Which horse has the greatest linear speed?

Three different bodies-a uniform sphere, a uniform disk, and a hoop-all have same radius and same mass. The body with the largest rotational inertia will be

In a stable stack of identical boards at the edge of a table, the center of gravity of the top board

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