AP Physics Quiz 7.1

A disk rotates with an angular speed  $\omega$  . What is the linear speed v of a point on the disk located a distance r away from the axis of rotation?

•  $\omega r$  

•  $\frac{\omega}{r}$  

•  $\frac{r}{\omega}$  

•  $\omega^2r$  

Suppose a bicycle wheel of radius R rolls without slipping for a linear distance x. What is the angular displacement the bicycle wheel during this movement?

• $\theta=\frac{x}{r}$

• $\theta=\frac{r}{x}$

• $\theta=xr$

• $\theta=xr^2$

If the translational velocity of an object is 3 m/s, and is located a distance of 2 m from the axis of rotation, what is the object's angular velocity?

• 0.67 rad/s
• 1.5 rad/s
• 5 rad/s
• 6 rad/s

A fan spins with a constant angular speed of 500 radians/second. How long will it take to cover an angle of 2π radians (one revolution)?

• 0.013 s
• 0.002 s
• 76.9 s
• 6.28 s

A 0.12-m-radius grinding wheel takes 5.5 s to speed up from 2.0 rad/s to 11.0 rad/s. What is the wheel's average angular acceleration?

• 0.20 rad/s/s

• 4.81 rad/s/s

• 3.12 rad/s/s

• 1.63 rad/s/s

A fan blade, initially at rest, rotates with a constant acceleration of 0.025 rad/s². What is its angular speed at the instant it goes through an angular displacement of 4.2 rad?

• 0.025 rad/s

• 0.11 rad/s

• 0.46 rad/s

• 0.21 rad/s

A fan blade, initially at rest, rotates with a constant acceleration of 0.025 rad/s². What is the time interval required for it to reach a 4.2 rad displacement after starting from rest

• 12.96 s

• 168 s

• 336 s

• 18.33 s

A wrench is used to tighten a nut. A 15N perpendicular force is applied 50cm away from the axis of rotation, and moves a distance of 10 cm as it turns. What is the torque applied to the wrench?

• 7.5 Nm
• 1.5 Nm
• 750 Nm
• 150 Nm

Find the magnitude of the torque produced by a 5.0 N force applied to a door at a perpendicular distance of 65 cm from the hinge.

• 75 Nm
• 3.25 Nm
• 6.3 Nm
• 8.75 Nm

The easiest way to open a heavy door  is by applying the force

• Near the hinges
• In the middle of the door
• At the edge of the door far from the hinges
• At the top of the door