Moment of Inertia and Rotational Kinetic Energy

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

The moment of inertia:

• is synonymous with mass

• does not depend on where the mass is located

• resistance to a change in angular velocity

• more resistance to change = less inertia

The property of a body to resist change in motion.

• mass
• weight
• volume
• inertia

Tags

NGSS.HS-PS2-1

The figure shows scale drawings of four objects, each of the same mass and uniform thickness, with the mass distributed uniformly. Which one has the greatest moment of inertia when rotated about an axis perpendicular to the plane of the drawing at point P?

• A
• B
• C
• D

A solid sphere, solid cylinder, and a hollow pipe all have equal masses and radii. If the three of them are released simultaneously at the top of an inclined plane and do not slip, which one will reach the bottom first?

• cylinder
• pipe
• sphere
• They all reach the bottom at the same time.

Tags

NGSS.HS-PS2-1

Two uniform solid balls, one of radius R and mass M, the other of radius 2R and mass 8M, roll down a high incline. They start together from rest at the top of the incline. Which one will reach the bottom of the incline first?

• The small sphere arrives first.
• The large sphere arrives first.
• Both reach the bottom at the same time.

Tags

NGSS.HS-PS2-1

Suppose you are designing an engineless car for a downhill coasting race.  What type of wheels would be the best?

• Solid disks.
• Hoops.
• Hollow cylinders.
• Diamond encrusted triangles.

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NGSS.HS-ETS1-2

NGSS.HS-ETS1-3

A uniform solid cylinder with a radius of 10 cm and a mass of 3.0 kg is rotating about its center with an angular speed of 33.4 rpm. What is its kinetic energy?

• 0.092 J
• 17 J
• 1.1 J
• 0.18 J

Tags

NGSS.HS-PS3-1

Three 5 kg masses attached to strings that are 12.3 cm long are spinning at 100 revolutions per minute. What is the moment of inertia of the system? Find answer in the unit kg*m². Use two significant digits.

(a)  

Three 5 kg masses attached to strings that are 12.3 cm long are spinning at 100 revolutions per minute. What is the rotational kinetic energy of the system? Find answer in Joules. Use two significant digits.

(a)