Focus -- Rotational Motion

Which has greater angular velocity, 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 have the same angular velocity

The easiest way to open a heavy door is by applying 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 wrench is used to tighten a nut. A 15 N perpendicular force is applied 50 cm away from the axis of rotation and moves a distance of 10 cm as it turns. What is the torque applied to the wrench?

• 7.5 Nm

• 750 Nm

• 1.5 Nm

• 150 Nm

A figure skater is spinning with his arms outstretched. What happens to his moment of inertia when pulls his arms inward toward his body?

• Moment of inertia increases

• Moment of inertia decreases

• Moment of inertia stays the same

At what angle should the force be applied to a wrench to produce the maximum torque?

• 0^o to the handle

• 90^o to the handle

• 180^o to the handle

• 3600^o to the handle

In order to do a lot of flips an Olympic diver would want:

• A high rotational inertia

• A low rotational inertia

• A low linear acceleration

• A low angular velocity

If, at a location of 2 m from the axis of rotation, the translational velocity of an object is 3 m/s, what is the object's angular velocity?

• 0.67 rad/s

• 1.5 rad/s

• 5 rad/s

• 6 rad/s

Where is the center of mass of a baseball bat located?

• Exactly halfway along the bat

• In the thin handle

• In the thicker end of the bat