Master Rotational Motion in Physics: Interactive Quizzes and Practice

Question 1

If the angular velocity of a rotating rigid body doubles, what happens to its angular momentum?

Accepted Answer

It becomes twice as great.

Answer

It becomes four times greater.

Answer

It remains the same.

Answer

It becomes half as great.

Question 2

When a force F is applied at a distance r from the axis of rotation, the torque produced is:

Accepted Answer

Fr

Answer

F/r

Answer

rF

Answer

Fr^2

Question 3

Which of the following is the unit of angular momentum?

Accepted Answer

kg m^2/s

Answer

J s

Answer

m^2/s

Answer

kg m/s

Question 4

A particle moving in a circular path with constant speed has acceleration directed:

Accepted Answer

Towards the center of the circle

Answer

Away from the center of the circle

Answer

Along the tangent to the circle

Answer

Perpendicular to the circle

Question 5

Which of the following is the SI unit of torque?

Accepted Answer

N m

Answer

J

Answer

kg m^2/s^2

Answer

rad/s

Question 6

The moment of inertia of a thin rod rotating about an axis perpendicular to its length and passing through its center is:

Accepted Answer

(1/12)ML^2

Answer

(1/2)ML^2

Answer

ML^2

Answer

2ML^2

Question 7

When the net torque on a rotating object is zero, the object:

Accepted Answer

Is moving with constant angular velocity.

Answer

Is not accelerating.

Answer

Is accelerating linearly.

Answer

Is accelerating rotationally.

Question 8

Which of the following is not a conserved quantity in rotational motion?

Accepted Answer

Torque

Answer

Angular momentum

Answer

Energy

Answer

Linear momentum

Question 9

When the angular velocity of a rotating body changes at a constant rate, the body is undergoing:

Accepted Answer

Uniformly accelerated rotational motion

Answer

Uniform circular motion

Answer

Harmonic motion

Answer

Simple harmonic motion

Question 10

A particle moves in a circular path with a constant linear velocity. What is the relationship between its linear velocity (v) and angular velocity (ω)?

Accepted Answer

v = ωr

Answer

v = ω

Answer

v = ω/r

Answer

v is not related to ω.

Question 11

A solid sphere of mass M and radius R is rolling without slipping down an inclined plane of angle θ. What is the acceleration of the sphere down the plane?

Accepted Answer

g sin θ

Answer

g cos θ

Answer

g

Answer

0

Question 12

For rolling motion without slipping to occur, which condition must be satisfied?

Accepted Answer

Linear velocity at the point of contact is zero

Answer

Rotational acceleration is zero

Answer

Translational acceleration is zero

Answer

Angular velocity is constant

Question 13

In rotational motion, which quantity is conserved?

Accepted Answer

Angular momentum

Answer

Linear momentum

Answer

Velocity

Answer

Energy

Question 14

A rigid body is rotating about a fixed axis. If the torque acting on the body increases while the angular velocity remains constant, what will happen to the rate of change of angular momentum?

Accepted Answer

The rate of change of angular momentum will increase.

Answer

The angular acceleration of the body will remain constant.

Answer

The moment of inertia of the body will remain constant.

Question 15

The kinetic energy of a rotating body is directly proportional to which quantity?

Accepted Answer

The square of its angular velocity

Answer

The moment of inertia

Answer

The radius of gyration

Answer

The angular velocity

Question 16

What is the relationship between the linear velocity (v) and angular velocity (ω) for an object moving in a circular path of radius (r)?

Accepted Answer

v = rω

Answer

v = 2πrω

Answer

v = ω / r

Question 17

A flywheel of radius **R** and moment of inertia **I** is rotating with angular velocity ω. What is the kinetic energy stored in the flywheel?

Accepted Answer

**1/2*I*ω^2**

Answer

**1/4*I*ω^2**

Answer

**2*I*ω^2**

Answer

**I*ω^2**

Question 18

A uniform disk of radius **R** and mass **M** is rolling without slipping on a horizontal surface. What is its total kinetic energy?

Accepted Answer

**1/2*MV^2 + 1/4*MR^2*ω^2**

Answer

**1/4*MR^2*ω^2**

Answer

**MV^2 + MR^2*ω^2**

Answer

**1/2*MV^2**

Question 19

A particle of mass **m** is moving in a circular path of radius **r** with a constant speed **v**. What is the work done by the centripetal force?

Accepted Answer

**0**

Answer

**1/2*mv^2**

Answer

**mv^2**

Answer

**-mv^2**