Torque and Angular Motion

Which of the following is the unit for angular displacement?

• meters
• seconds
• radians
• radians per second

A rod rotates about a pivot at its center at 2 rads/s. Its angular velocity increases to 14 rads/s in 3 s. Find the rod's angular acceleration

• 2 rad/s/s
• 4 rad/s/s
• 6 rad/s/s
• 8 rad/s/s

A record on a turntable is spinning and is coming to rest. If the angular velocity is 20.0 rad/s and the record slows at a rate of - 5 rad/s/s, how long does it take the record to come to rest? 

• 2 s
• 4 s
• 12 s 
• 8 s 

A ball attached to a string and rotates in a circle. If it takes 1.00 s to complete one revolution, what is the angular velocity of the ball?

• 3.14 rad/s
• 6.28 rad/s
• 9.42 rad/s
• 12.6 rad/s

Torque is the rotational analog of which of the following quantities?

• kinetic energy
• linear momentum
• force
• acceleration

 2600 rev/min is equivalent to which of the following?

• 2600 rad/s 
• 43.3 rad/s 
• 273 rad/s
• 60 rad/s

A grindstone spinning at the rate of 8.3 rev/s has what approximate angular speed?

• 3.2 rad/s
• 26 rad/s
• 52 rad/s
• 81 rad/s

A spool of thread has an average radius of 1.00 cm. If the spool contains 62.8 m of thread, how many turns of thread are on the spool? "Average radius" allows us to not need to treat the layering of threads on lower layers.

• 100
• 1000
• 3140
• 62800

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   

• 1.8 s
• 2.0 s
• 16 s
• 18 s

If the torque required to loosen a nut on the wheel of a car has a magnitude of 60.0 N• m, what minimum perpendicular force must be exerted by a mechanic at the end of a 45.0 cm wrench to loosen the nut?

• .666 Nm
•  133.3 N
• 66.7 N
• 13.3 Nm