Multiple Choice

What is 1 radian approximately in degrees?

1. 57.3°
2. 360°
3. π°
4. 2π°

If the following objects are spinning at the same angular velocities, the edge of which one would have the highest speed?

1. Mini CD
2. Regular CD
3. Vinyl record

1. $\text{m/s}$
2. $\text{rad/s}$
3. ${}^{\circ <!--\; \circ \; -->}\text{/s}$

1. $\frac{\mathrm{\pi <!--\; \pi \; -->}}{12}$
2. $\frac{\mathrm{\pi <!--\; \pi \; -->}}{9}$
3. $\frac{\mathrm{\pi <!--\; \pi \; -->}}{6}$
4. $\frac{\mathrm{\pi <!--\; \pi \; -->}}{3}$

1. The arc length is directly proportional to the angle of rotation, so it increases with the angle of rotation.
2. The arc length is inversely proportional to the angle of rotation, so it decreases with the angle of rotation.
3. The arc length is directly proportional to the angle of rotation, so it decreases with the angle of rotation.
4. The arc length is inversely proportional to the angle of rotation, so it increases with the angle of rotation.

Which of these quantities is constant in uniform circular motion?

1. Speed
2. Velocity
3. Acceleration
4. Displacement

Which of these quantities impact centripetal force?

1. Mass and speed only
2. Mass and radius only
3. Speed and radius only
4. Mass, speed, and radius all impact centripetal force

An increase in the magnitude of which of these quantities causes a reduction in centripetal force?

1. Mass
2. Radius of curvature
3. Speed

1. It increases, because the centripetal acceleration is inversely proportional to the radius of the curvature.
2. It increases, because the centripetal acceleration is directly proportional to the radius of curvature.
3. It decreases, because the centripetal acceleration is inversely proportional to the radius of the curvature.
4. It decreases, because the centripetal acceleration is directly proportional to the radius of the curvature.

1. Centripetal acceleration is inversely proportional to the radius of curvature, so it increases as the radius of curvature decreases.
2. Centripetal acceleration is directly proportional to the radius of curvature, so it decreases as the radius of curvature decreases.
3. Centripetal acceleration is directly proportional to the radius of curvature, so it decreases as the radius of curvature increases.
4. Centripetal acceleration is directly proportional to the radius of curvature, so it increases as the radius of curvature increases.

Which of these quantities is not described by the kinematics of rotational motion?

1. Rotation angle
2. Angular acceleration
3. Centripetal force
4. Angular velocity

In the equation $$\tau \text{ = }rF\text{sin}\theta$$, what is F?

1. Linear force
2. Centripetal force
3. Angular force

1. Angular velocity is zero.
2. Angular acceleration is zero.

1. $a=r\mathrm{\alpha <!--\; \alpha \; -->}$
2. $a=\frac{\mathrm{\alpha <!--\; \alpha \; -->}}{r}$
3. $a=r^2\mathrm{\alpha <!--\; \alpha \; -->}$
4. $a=\frac{\mathrm{\alpha <!--\; \alpha \; -->}}{r^2}$