Rotational Motion Review

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

Tags

NGSS.HS-PS2-1

Torque can be positive or negative.

• True

• False

Which of the following is NOT a unit of rotational speed?

• Meters per second

• Revolutions per minute

• Revolutions per second

• Rotations per second

Which has a 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 - they both have the same angular speed

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

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

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

• Increase

• Decrease

• Stays the same

• Is lost

Tags

NGSS.HS-PS2-2