The graph shows the angular velocity and angular acceleration versus time for a rotating body. At which of the following times is the rotation speeding up at the greatest rate?

1. t = 1 s

2. t = 2 s

3. t = 3 s

4. t = 4 s

5. t = 5 s

Q9.1

The graph shows the angular velocity and angular acceleration versus time for a rotating body. At which of the following times is the rotation speeding up at the greatest rate?

1. t = 1 s

2. t = 2 s

3. t = 3 s

4. t = 4 s

5. t = 5 s

A9.1

A DVD is initially at rest so that the line PQ on the disc’s surface is along the +x-axis. The disc begins to turn with a constant z = 5.0 rad/s2.

At t = 0.40 s, what is the angle between the line PQ and the +x-axis?

Q9.2

1. 0.40 rad

2. 0.80 rad

3. 1.0 rad

4. 2.0 rad

1. 0.40 rad

2. 0.80 rad

3. 1.0 rad

4. 2.0 rad

A9.2

A DVD is initially at rest so that the line PQ on the disc’s surface is along the +x-axis. The disc begins to turn with a constant z = 5.0 rad/s2.

At t = 0.40 s, what is the angle between the line PQ and the +x-axis?

A DVD is rotating with an ever-increasing speed.

Compared to the point P on the disc’s surface, the point Q on the disc’s surface has

1. the same centripetal acceleration and the same tangential acceleration

2. a greater centripetal acceleration and a greater tangential acceleration

3. a smaller centripetal acceleration and a smaller tangential acceleration

4. a greater centripetal acceleration and the same tangential acceleration

5. none of the above

Q9.3

A DVD is rotating with an ever-increasing speed.

Compared to the point P on the disc’s surface, the point Q on the disc’s surface has

1. the same centripetal acceleration and the same tangential acceleration

2. a greater centripetal acceleration and a greater tangential acceleration

3. a smaller centripetal acceleration and a smaller tangential acceleration

4. a greater centripetal acceleration and the same tangential acceleration

5. none of the above

A9.3

1. a faster linear speed and a faster angular speed

2. the same linear speed and a faster angular speed

3. a slower linear speed and the same angular speed

4. the same linear speed and a slower angular speed

5. none of the above

Q9.4

Compared to a gear tooth on the rear sprocket (on the left, of small radius) of a bicycle, a gear tooth on the front sprocket (on the right, of large radius) has

Compared to a gear tooth on the rear sprocket (on the left, of small radius) of a bicycle, a gear tooth on the front sprocket (on the right, of large radius) has

1. a faster linear speed and a faster angular speed

2. the same linear speed and a faster angular speed

3. a slower linear speed and the same angular speed

4. the same linear speed and a slower angular speed

5. none of the above

A9.4

All three of these objects are uniform, have the same mass, and have the same outer dimension. Which has the smallest moment of inertia about an axis through its center as shown?

1. the solid cylinder

2. the hollow cylinder

3. the rectangular solid

4. not enough information given to decide

Q9.5

All three of these objects are uniform, have the same mass, and have the same outer dimension. Which has the smallest moment of inertia about an axis through its center as shown?

1. the solid cylinder

2. the hollow cylinder

3. the rectangular solid

4. not enough information given to decide

A9.5