Home Chapter 8 Practice Questions

# Practice Questions

This activity contains 25 questions.

## A wheel of radius 1 m is spinning with a constant angular velocity of 2 rad/s. What is the centripetal acceleration of a point on the wheel's rim?

 0.5 m/s2 1 m/s2 2 m/s2 4 m/s2

## A wheel of radius .5 m is spinning with a constant angular velocity of 2 rad/s. What is the centripetal acceleration of a point on the wheel's rim?

 0.5 m/s2 1 m/s2 2 m/s2 4 m/s2

## A non-zero net torque will

 cause a change in angular velocity. maintain a constant angular velocity. cause linear acceleration. maintain a constant angular momentum.

## A zero net torque

 will produce a change in angular momentum. will conserve angular momentum. will conserve linear momentum. will change angular velocity.

## An ice skater is in a spin with his arms outstretched. If he pulls in his arms, what happens to his rotational kinetic energy?

 It increases. It decreases. It remains constant but non-zero. It remains zero.

## Marilyn (M) and her twin sister Sheila (S) are riding on a merry-go-round revolving at a constant rate. Sheila is half way in from the edge, as shown (bird's-eye view).

 They have different speeds, and different angular velocities. They have the same speed, but their angular velocity is different. They have different speeds, but the same angular velocity. They have the same speed and the same angular velocity.

Marilyn (M) and her twin sister Sheila (S) are riding on a merry-go-round revolving at a constant rate. Sheila is half way in from the edge, as shown (bird's-eye view).

What is the relationship between Marilyn's and Sheila's angular acceleration?

 Marilyn's is greater than Sheila's. Sheila's is greater than Marilyn's. It is the same for both and non-zero. It is the same for both and equals zero.

Marilyn (M) and her twin sister Sheila (S) are riding on a merry-go-round revolving at a constant rate. Sheila is half way in from the edge, as shown (bird's-eye view).

What is the relationship between the centripetal (radial) acceleration of the two sisters?

 Marilyn's is 8 times greater than Sheila's. Marilyn's is 4 times greater than Sheila's. Marilyn's is twice as great as Sheila's. They are the same.

Marilyn (M) and her twin sister Sheila (S) are riding on a merry-go-round revolving at a constant rate. Sheila is half way in from the edge, as shown (bird's-eye view).

What is the relationship between the angular momentum of the two sisters?

 Marilyn's is 8 times greater than Sheila's. Marilyn's is 4 times greater than Sheila's. Marilyn's is twice as great as Sheila's. They are the same.

Marilyn (M) and her twin sister Sheila (S) are riding on a merry-go-round revolving at a constant rate. Sheila is half way in from the edge, as shown (bird's-eye view).

What is the relationship between the rotational kinetic energy of the two sisters?

 Marilyn's is 8 times greater than Sheila's. Marilyn's is 4 times greater than Sheila's. Marilyn's is twice as great as Sheila's. They are the same.

The record player on the turntable of your stereo is rotating clockwise (as seen from above). After turning it off, your turntable is slowing down, but hasn't stopped yet. The direction of the acceleration of Point P (at the left) is

Initially, a 2.00-kg mass is whirling at the end of a string (in a circular path of radius 0.750 m) on a horizontal frictionless surface with a tangential speed of 5 m/s. The string has been slowly winding around a vertical rod, and a few seconds later the length of the string has shortened to 0.250 m. What is the instantaneous speed of the mass at the moment the string reaches a length of 0.250 m?

 3.9 m/s 15 m/s 45 m/s 75 m/s

Initially, a 2.00-kg mass is whirling at the end of a string (in a circular path of radius 0.750 m) on a horizontal frictionless surface with a tangential speed of 5 m/s. The string has been slowly winding around a vertical rod, and a few seconds later the length of the string has shortened to 0.250 m. What is the initial centripetal acceleration of the mass?

 33.3 m/s2 100 m/s2 300 m/s2 900 m/s2

Initially, a 2.00-kg mass is whirling at the end of a string (in a circular path of radius 0.750 m) on a horizontal frictionless surface with a tangential speed of 5 m/s. The string has been slowly winding around a vertical rod, and a few seconds later the length of the string has shortened to 0.250 m. What is the final centripetal acceleration of the mass?

 33.3 m/s2 100 m/s2 300 m/s2 900 m/s2

## The three 'point' 1 kg masses in the figure are at (x,y) = (0,0),(4,3), and (8,0), respectively. What is the rotational inertia about an axis perpendicular to the figure and through the mass in the lower left hand corner?

 25 kg·m2 41 kg·m2 64 kg·m2 89 kg·m2

The three 'point' 1 kg masses in the figure are at (x,y) = (0,0),(4,3), and (8,0), respectively. What is the rotational inertia of the masses in the figure about an axis perpendicular to the figure and through the point half way between the two lower masses at (x,y) = (4,0)?

 25 kg·m2 41 kg·m2 64 kg·m2 89 kg·m2

## The three 'point' 1 kg masses in the figure are at (x,y) = (0,0),(4,3), and (8,0), respectively. What is the rotational inertia of the masses about the x axis?

 80 kg·m2 41 kg·m2 25 kg·m2 9 kg·m2

## The three 'point' 1 kg masses in the figure are at (x,y) = (0,0),(4,3), and (8,0), respectively. What is the rotational inertia of the masses about the y axis?

 80 kg·m2 41 kg·m2 25 kg·m2 9 kg·m2

## A bicycle is travelling North. The direction of the angular momentum vector of its front wheel is

 North. East. South. West.

## ( w is the angular velocity, t is the torque, a is the angular acceleration, I is the rotational inertia, and L the angular momentum.) Given the above definitions, F is to t as _______ is to I.

 p x a m

## What is the magnitude of the torque exerted by the F1 force on the door?

 0 N·m 5 N·m 7.1 N·m 10 N·m 20 N·m

## What is the magnitude of the torque exerted by the F2 force on the door?

 0 N·m 5 N·m 7.1 N·m 10 N·m 20 N·m

## What is the magnitude of the torque exerted by the F3 force on the door ?

 0 N·m 5 N·m 7.1 N·m 10 N·m 20 N-m

## What is the magnitude of the torque exerted by the F4 force on the door?

 0 N·m 5 N·m 7.1 N·m 10 N·m 20 N·m

## What is the magnitude of the torque exerted by the F5 force on the door?

 0 N·m 5 N·m 7.1 N·m 10 N·m 20 N·m