Physics 11-12 Torque & Angular Momentum

When an object is experiencing a net torque

• it is in dynamic equilibrium.
• it is in static equilibrium.
• it is rotating.
• it is translating.

Two children are sitting on a see-saw, as shown. Calculate the distance the 500-N child should sit from the fulcrum in the center (pivot) of the lever to balance the see-saw.

• 1.8 m

• 3m

• 5 m

• 1 m

Tags

NGSS.MS-PS2-2

If the torque required to loosen a nut on the wheel of a car has a magnitude of 60.0 N• m, what minimum perpendicular force must be exerted by a mechanic at the end of a 0.45 m wrench to loosen the nut?

• .666 Nm

• 133.3 N

• 66.7 N

• 13.3 Nm

If the torque required to loosen a nut on the wheel of a car has a magnitude of 60.0 N• m, for a 0.45 m wrench to loosen the nut, how much torque would be needed if a pipe extended the length of the wrench to 0.90 m?

• 60 Nm

• 30 Nm

• 120 Nm

• 54 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

Which person will topple over?

• Person A

• Person B

• Person C

Tags

NGSS.HS-PS2-1

Why are you more stable when riding a bicycle at a faster speed?

• You have more mass

• The wheels have angular momentum

• It's not easier to ride at a faster speed

• The bike has more momentum

Tags

NGSS.HS-PS2-2

A skater start spinning on the tips of her skates at low angular velocity with arm outstretched.

What would happen when she brings her arms close to her body

• She will spin slower

• She will spin faster

• She will spin at the same velocity

If a child is sitting on the outside edge of a merry-go-round and you push it to double the rotational velocity (ω) from 5 rpm to 10 rpm, what happens to the angular momentum (L)?

• the angular momentum doubles

• the angular momentum is reduced by half

• the angular momentum quadruples

Why would it be harder to stop the merry-go-round at 10 rotations per minute that when it was going 5 rotations per minute?

• the angular momentum is greater with a higher angular velocity and will require a larger torque to stop the motion.

• it won't because the angular momentum is the same for both angular speeds.