Rotational motion test review

Which has more rotational inertia? (all objects have the same radius and mass)

• Hollow sphere
• solid sphere
• disk
• cylinder

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

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?

• 9.6 rad/s/s
• 4.8 rad/s/s
• 3.1 rad/s/s
• 1.6 rad/s/s

A flywheel starts from rest, and has an angular acceleration of 4 rad/s². What will be its angular speed when it has made one revolution? 

• 5.01 rad/s
• 50.27 rad/s
• 2.83 rad/s
• 7.09 rad/s

A particular motor can provide a maximum of 110 Nm of torque. Assuming that all of this torque is used to accelerate a solid, uniform wheel of mass 10 kg and radius 3.00m how long will it take for the flywheel to accelerate from rest to 8.51 rad/s?

• 4.21 s

• 2.96 s

• 4.56 s

• 3.48 s

Tags

NGSS.HS-PS2-1

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

A gear spins at a rate of 400 revolutions/minute. Which choice is closest to its angular speed in radians/second?

• 6.67 rad/s

• 2500 rad/s

• 41.9 rad/s

• 20.9 rad/s

A wrench is used to tighten a nut. A 15N perpendicular force is applied 50cm away from the axis of rotation. What is the torque applied to the wrench?

• 7.5 Nm

• 1.5 Nm

• 750 Nm

• 150 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

A tire of 68cm in diameter travels 9.2km. How many revolutions does it make?

• 43.00 rads
• 567 revs
• 4300 revs
• 68cm