Rotational Motion and Rotational Dynamics

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

Which has greater angular 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

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

• Meters per second

• Revolutions per minute

• Revolutions per second

• Rotations per second

What is the direction of the force that acts on clothes in the spin cycle of a washing machine?

• Inward
• Down
• Outward
• Up

Tags

NGSS.HS-PS2-1

A tin can whirled on the end of a string moves in a circle because 

• the can continually pulls on the string.
• once the can starts moving, that is its natural tendency.
• there is a force on the can pulling it outward.
• there is an inward force acting on the can.

Tags

NGSS.HS-PS2-1

If you whirl a tin can on the end of a string and the string suddenly breaks, the can will 

• fly directly away from you.
• fly off, tangent to its circular path.
• fly directly toward you.
• spiral away from your hand.

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NGSS.HS-PS2-1

NGSS.HS-PS2-2

A ladybug rests on the bottom of a tin can that is being whirled horizontally on the end of a string. Since the ladybug, like the can, moves in a circle, there must be a force on it. What exerts this force?

• Gravity
• The string
• Your hand
• The can

Tags

NGSS.HS-PS2-1

"Centrifugal forces" are an apparent reality to observers in a reference frame that is 

• rotating.
• an inertial reference frame.
• moving at constant velocity.
• at rest.

A person weighs less at the equator than at the poles. The reason for this has to do with the 

• tidal bulges.
• influence of the sun, moon, and all the planets.
• higher temperature at the equator, and expansion of matter.
• spin of the Earth.

Tags

NGSS.HS-PS2-4

As the rotational speed of a space habitat increases, the weight of people inside 

• decreases
• increases
• stays the same

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NGSS.HS-PS2-4