Rotary Motion

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

• 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

Which object listed below has the greatest momentum?

• A 0.05 kg object rolling at 0.2 m/s.
• A 0.15 kg object rolling at 2 m/s.
• A 0.15 kg object rolling at 1 m/s
• A 0.4 kg object rolling at 2 m/s.

Tags

NGSS.HS-PS2-2

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

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 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

Which travels faster?

• A rotating ball
• a non rotating ball
• a honey badger

Tags

NGSS.MS-PS3-1

A small mass is rotating without friction in a circle. The string is shortened by pulling it through the axis of rotation with no external torque. What happens to the tangential velocity?

• It increases
• It decreases
• It stays the same

Suppose you are rotating in a chair with 2 equal masses held in each outstretched hand and you drop them. What happens to your angular velocity?

• Increase
• Decrease
• Stays the same
• Is lost

Tags

NGSS.HS-PS2-2