1 A bicycle wheel rotates uniformly through 4.0 revolutions in 4.0 s. What is the linear speed of a point 0.10 m from the center of the wheel?

a. 0.53 rad/s

b. 0.63 rad/s

c. 0.46 rad/s

d. 0.79 rad/s

2 A bicycle wheel rotates uniformly through 4.0 revolutions in 16 s. What is the period of the wheel's rotation?

a. 0.50 s

b. 2.0 s

c. 4.0 s

d. 8.0 s

3 A bicycle wheel rotates uniformly through 4.0 revolutions in 16 s. What is the frequency of the wheel's rotation?

a. 0.25 Hz

b. 0.5 Hz

c. 1.0 Hz

d. 2.0 Hz

4 A boy and a girl are riding on a merry-go-round which is turning at a constant rate. The boy is near the outer edge, and the girl is closer to the center. Who has the greater angular speed?

a. The boy

b. The girl

c. Both have the same non-zero angular velocity.

d. Both have zero angular velocity.

5 A boy and a girl are riding a merry-go-round which is turning at a constant rate. The boy is near the outer edge, while the girl is closer to the center. Who has the greater centripetal acceleration?

a. The boy

b. The girl

c. Both have the same non-zero centripetal acceleration.

d. Both have zero centripetal acceleration.

6 A boy and a girl are riding on a merry-go-round which is turning at a constant rate. The boy is near the outer edge, and the girl is closer to the center. Who has the greater linear speed?

a. The boy.

b. The girl.

c. Both have the same non-zero translational velocity.

d. Both have zero translational velocity.

7 Angular velocity is expressed in units of

a. meters per second.

b. radians per second.

c. omegas per second.

d. arcs per second.

8 The minute hand of a clock has a length of 0.30 m. What distance does the tip of the minute hand sweep through in 15 minutes?

a. 0.12 m

b. 0.24 m

c. 0.36 m

d. 0.47 m

9 A phonograph record rotates at 78 rpm. Through what angle does it turn in 0.20 s?

a. 94 degrees

b. 100 degrees

c. 86 degrees

d. 96 degrees

10 Consider a rigid body that is rotating. Which of the following is an accurate statement?

a. Its center of rotation is its center of gravity.

b. All points on the body are moving with the same angular velocity.

c. All points on the body are moving with the same linear velocity.

d. Its center of rotation is at rest, i.e., not moving.

11 A pulsar (a rotating neutron star) emits pulses at a frequency of 0.80 kHz. The period of its rotation is

a. 1.25 ms

b. 2.5 s

c. 0.125 s

d. 25 ms

12 A wheel of diameter 36 cm turns at 2500 rpm. How far will a point on the outer rim move in 4.0 s?

a. 3.1 m

b. 189 m

c. 90 m

d. 167 m

13 A wheel is rotating at 5.50 rpm. Through what angle will a point on the rim turn in 15.00 s?

a. 570 degrees

b. 495 degrees

c. 294 degrees

d. 360 degrees

14 A car is negotiating a flat circular curve of radius 50 m with a speed of 20 m/s. The maximum centripetal force (provided by static friction) is 1.2X10^4 N. What is the centripetal acceleration of the car?

a. 0.40 m/s^2

b. 0.80 m/s^2

c. 4.0 m/s^2

d. 8.0 m/s^2

15 A car is negotiating a flat circular curve of radius 50 m with a speed of 20 m/s. The maximum centripetal force (provided by static friction) is 1.2X10^4 N. What is the mass of the car?

a. 0.50X10^3kg

b. 1.0X10^3kg

c. 1.5X10^3kg

d. 2.0X10^3kg

16 A flywheel, of radius 1.0 m, is spinning with a constant angular velocity of 2.0 rad/s. What is the centripetal acceleration of a point on the wheel's rim?

a. 1.0 m/s^2

b. 2.0 m/s^2

c. 4.0 m/s^2

d. None of the above.

17 What is the centripetal acceleration of a point on the perimeter of a bicycle wheel of diameter 70.0 cm when the bike is moving 8.00 m/s?

a. 91.0 m/s^2

b. 183 m/s^2

c. 206 m/s^2

d. 266 m/s^2

18 A 0.300-kg mass, attached to the end of a 0.750-m string, is whirled around in a smooth level table. If the maximum tension that the string can withstand is 250 N then what maximum linear speed can the mass have if the string is not to break?

a. 19.4 m/s

b. 22.4 m/s

c. 25.0 m/s

d. 32.7 m/s

19 A wheel accelerates with a constant angular acceleration of 3.5 rad/s‚. If the initial angular velocity is 2.0 rad/s, what is the angle the wheel rotates through in 2.0 s?

a. 11 rad

b. 7.0 rad

c. 3.5 rad

d. 5.5 rad

20 A wheel accelerates with a constant angular acceleration of 3.5 rad/s‚. If the initial angular velocity is 2.0 rad/s, what is the angular velocity at t = 2.0 s?

a. 2.0 rad/s

b. 5.0 rad/s

c. 7.0 rad/s

d. 9.0 rad/s

21 A wheel starts at rest, and has an angular acceleration of 4 rad/s‚. Through what angle does it turn in 3.0 s?

a. 36 rad

b. 18 rad

c. 12 rad

d. 9.0 rad

22 A Ferris wheel rotating at 20 rad/s decelerates with a constant angular acceleration of -5.0 rad/s‚. How many revolutions does it rotate before coming to rest?

a. 40

b. 20

c. 6.4

d. 3.2

23 How many radians does a 0.300-m radius automobile tire rotate after starting from rest and accelerating at a constant angular acceleration of 2.00 rad/s‚ over a 5.00-s interval?

a. 1.00 rad

b. 2.00 rad

c. 12.5 rad

d. 25.0 rad

24 A wheel of diameter of 68.0 cm slows down uniformly from 8.40 m/s to rest over a distance of 115 m. How long does it take for the wheel to come to the stop?

a. 24.7 s

b. 27.4 s

c. 42.7 s

d. 47.2 s

25 The bolts on a car wheel require tightening to a torque of 70 Nm. If a 20 cm long wrench is used, what is the magnitude of the force required when the force is perpendicular to the wrench?

a. 350 N

b. 250 N

c. 300 N

d. 150 N

26 The bolts on a car wheel require tightening to a torque of 90 Nm. If a 30 cm long wrench is used, what is the magnitude of the force required when the force is 53 degrees to the wrench?

a. 190 N

b. 380 N

c. 19 N

d. 38 N

27 A uniform solid sphere has mass M and radius R. If these are increased to 2M and 3R, what happens to the sphere's moment of inertia about a central axis?

a. Increases by a factor of 6.

b. Increases by a factor of 12.

c. Increases by a factor of 18.

d. Increases by a factor of 54.

28 What is the quantity used to measure an object's resistance to changes in rotation?

a. mass

b. moment of inertia

c. torque

d. angular velocity

29 Two uniform solid spheres have the same mass, but one has 3 times the radius of the other. The ratio of the larger sphere's moment of inertia to that of the smaller sphere is

a. 20/5

b. 28/5

c. 3

d. 9

30 Consider two uniform solid spheres where one has twice the

mass and twice the diameter of the other. The ratio of the

larger moment of inertia to that of the smaller moment of

inertia is

a. 2

b. 8

c. 4

d. 10

31 Consider two uniform solid spheres where both have the same diameter, but one has twice the mass of the other. The ratio of the larger moment of inertia to that of the smaller moment of inertia is

a. 2

b. 8

c. 10

d. 4

32 If a constant net torque is applied to an object, that object will

a. rotate with constant angular velocity.

b. rotate with constant angular acceleration.

c. having an increasing moment of inertia.

d. having a decreasing moment of inertia.

33 A wheel with moment of inertia 2.00 kgm‚ has a net torque of 2.50 Nm applied to it. What angular acceleration does it experience?

a. 0.200 rad/s^2

b. 1.25 rad/s^2

c. 2.00 rad/s^2

d. 2.50 rad/s^2

34 An ice skater performs a pirouette (a fast spin) by pulling in his outstretched arms close to his body. What happens to his moment of inertia about the axis of rotation?

a. It does not change.

b. It increases.

c. It decreases.

d. It changes, but it is impossible to tell which way.

35 An ice skater performs a pirouette (a fast spin) by pulling in his outstretched arms close to his body. What happens to his angular momentum about the axis of rotation?

a. It does not change.

b. It increases.

c. It decreases.

d. It changes, but it is impossible to tell which way.

36 An ice skater performs a pirouette (a fast spin) by pulling in his outstretched arms close to his body. What happens to his rotational kinetic energy about the axis of rotation?

a. It does not change.

b. It increases.

c. It decreases.

d. It changes, but it is impossible to tell which way.

37 An object's angular momentum changes by 10 kgm‚/s in 2.0 s. What magnitude average torque acted on this object?

a. 40 Nm

b. 2.5 Nm

c. 20 Nm

d. 5.0 Nm

38 The earth orbits the sun in an elliptical orbit. Ignore any friction which may be present. What happens over time to the earth's angular momentum about the sun?

a. It continually increases.

b. It continually decreases.

c. It remains constant.

d. It increases during some parts of the orbit, and decreases during others.

39 "The total angular momentum of a system of particles changes when a net external force acts on the system." This statement is

a. always true.

b. never true.

c. sometimes true. It depends on the force's magnitude.

d. sometimes true. It depends on the force's point of application.

40 In what circumstances can the angular velocity of system of particles change without any change in the system's angular momentum?

a. This cannot happen under any circumstances.

b. This can happen if a net external force acts on the system's center of mass.

c. This can happen if the only forces acting are internal to the system.

d. This can happen if an external net torque is applied properly to the system.

41 An ice skater has a moment of inertia of 5.0 kgm‚ when her arms are outstretched. At this time she is spinning at 3.0 revolutions per second (rps). If she pulls in her arms and decreases her moment of inertia to 2.0 kgm‚, how fast will she be spinning?

a. 2.0 rps

b. 3.3 rps

c. 7.5 rps

d. 10 rps

42 A figure skater rotating at 5.00 rad/s with arms extended has a moment of inertia of 2.25 kgm‚. If the arms are pulled in so the moment of inertia decreases to 1.80 kgm‚, what is the final angular speed?

a. 2.25 rad/s

b. 4.60 rad/s

c. 6.25 rad/s

d. 0.81 rad/s

43 The earth moves about the sun in an elliptical orbit. As the earth moves close to the sun, then which of the following best describes the orbiting speed of the earth about the sun?

a. increases

b. decreases

c. remains constant

d. None of the above.

44 What arc length does the Earth travel in a 4 month period in its nearly circular orbit about the Sun with a radius of 2.5X10^11 m?

a. 4.2X10^11m

b. 4.8X10^11m

c. 5.2X10^11m

d. 6.0X10^11m

45 A wheel of radius 2.0 m is rotating with a constant angular speed of 3.0 rad/s. What is the centripetal acceleration of a point on the wheel's rim?

a. 1.50 m/s^2

b. 2.0 m/s^2

c. 9.0 m/s^2

d. 18 m/s^2

46 How many rad/s is 78 revolutions per minute equivalent to?

a. 4.4 rad/s

b. 8.2 rad/s

c. 9.4 rad/s

d. 8.8 rad/s

47 A wheel of radius 2.0 m is rotating with a constant angular speed of 4.0 rad/s. What is the linear speed of a point on the wheel's rim?

a. 2.50 m/s

b. 7.0 m/s

c. 8.0 m/s

d. 2.0 m/s

48 A bicycle wheel rotates uniformly through 4.0 revolutions in 4.0 s. What is the average angular speed of the wheel?

a. 6.79 rad/s

b. 5.6 rad/s

c. 6.3 rad/s

d. 9.3 rad/s