Rotational Dynamics Review

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 both have the same angular velocity

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 wrench is used to tighten a nut. A 15N perpendicular force is applied 50cm away from the axis of rotation, and moves a distance of 10 cm as it turns. What is the torque applied to the wrench?

HINTS: Torque = Force x Distance

50 cm = 1/2 meter

• 7.5 Nm

• 1.5 Nm

• 750 Nm

• 150 Nm

What happens to his Moment Of Inertia when a figure skater brings in his arms?

HINT: All formulae fir Moment Of Inertia involve the mass times the radius squared....

• Increase his rotational inertia

• Decrease his rotational inertia

• has no affect

Which represents the acceleration of the ball?

• A
• B
• C
• D

What's the centripetal acceleration of an object traveling 2.3 m/s around a circle of diameter 0.6 m?

• 5 m/s²

• 17.63 m/s²

• 10 m/s²

• 8.81 m/s²

Because a hollow ball has a higher moment of inertia than a solid ball...

• The solid ball rolls faster

• The solid ball weighs more.

• The solid ball weighs less.

• They both accelerate at the same rate.

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

• 0⁰ to the handle

• 90⁰ to the handle

• 180⁰ to the handle

• 360⁰ to the handle

Does this result make sense? If yes then why? if no, then Why not?