Question

1.) For a rotating rigid body which of the following statements is not correct?

a.) all points along a rotating rigid body move with constant speed

b.) points along a rotating body move through the same angle in equal time intervals

c.) point along a rotating body have velocities that continuously change directions

d.) all of the above

2.) Which of the following quantities will impact how a rigid body's rotational speed can change?

a.) the body's rotational inertia

b.)the net torque on the body

c.) the net force on body

d) a and b

e.) b and c

f.) all of above

3.)a radian is all of the following except

a.) a dimensionless quantity

b.) the ratio of arc length over radius

c.) same as degrees

d.) the unit for rotational position

4.) you exert a force on a friend who is holding a 4.0 m long rope. now suppose you exert the same force on a friend, but the friend is holding an 8.0 m long rope. How will this affect the rotational acceleration?

a. it will be quartered

b. halved

c. doubled

d. quadrupled

5.)if the angular speed of a rotating rigid body is doubled, how will its rotational kinetic energy change?

a. halved

b. stays the same

c. doubled

d. quadrupled

6.)a person with a moment of inertia I is spinning with an angular velocity w. what will the angular velocity of the person be if he changes his arm position such that his moment of interia changes to 3/4 I

a. 3/4 w

b.w

c. 4/3 w

7.) a person with moment of inertia I is spinning with an angular velocity w, by which factor will the kinetic energy of the person change if he moves his arm positions such that his moment of inertia changes to 2I

a. 1/4

b. 1/2

c. 2

d. 4

8.) consider two balls rolling down an inclined plane. one ball has a moment of inertia I and the other has a moment of inertia 2I. both balls start from rest at the same height and have the same mass. which ball will reach the bottom of the inclined plane first?

a. the ball with a moment of inertia I

b. ball with a moment of inertia 2I

c. same time

d. it is impossible to tell with the given information

Answer 1

Answer 1

Option. B

Points along a rotating body move through the same angle equal time interval .

Or we can say all point rotate same angle in equal time interval .That is angular speed of all point is same