Rotational Motion

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

• 2600 rad/s

• 86.67 rad/s

• 272.27 rad/s

• 136.14 rad/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 spool of thread has an average radius of 1.00 cm. If the spool contains 62.8 m of thread, about 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

• 10,000

• 10

A 0.30m radius automobile tire rotates how many radians after starting from rest and accelerating at a constant 2.0 rad/s² over a 5.0 s interval?

• 25 rad

• 12.5 rad

• 2 rad

• 0.5 rad

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 Ferris wheel starts at rest and builds up to a final angular speed of 0.70 rad/s while rotating through an angular displacement of 4.9 rad. What is its average angular acceleration?

• 0.07 rad/s/s

• 0.05 rad/s/s

• 1.8 rad/s/s

• 2.6 rad/s/s

A Ferris wheel, rotating initially at an angular speed of 0.50 rad/s, accelerates over a 7.0-s interval at a rate of 0.040 rad/s². What is its angular speed after this 7-s interval?

• 0.28 rad/s

• 0.33 rad/s

• 0.46 rad/s

• 0.78 rad/s

Which has more rotational inertia? (consider all objects have equal radius)

• Hollow sphere
• solid sphere
• cylindrical shell

• solid cylinder

Which has greater linear speed, a horse near the outside rail of a merry-go-round or a horse near the inside rail?

• the inside horse
• the outside horse
• Neither