Moment of Inertia Ideas

The moment of inertia:

• is synonymous with mass

• does not depend on where the mass is located

• resistance to a change in rotational motion

• more resistance to change = less inertia

A person sits on a freely spinning lab stool that has no friction in its axle. When this person extends her arms,

• her moment of inertia increases and her angular speed decreases.

• her moment of inertia decreases and her angular speed increases.

• her moment of inertia increases and her angular speed increases.

• her moment of inertia increases and her angular speed remains the same.

Which ball will be harder to get rolling?

• They will be equally hard to get rolling

• Ball #1

• Ball #2

• Not enough information

Which has the bigger effect on Moment Of Inertia

• Shape

• Speed

• Radius

• Mass

The train wheel in the picture has radius = 0.9 meter and it's mass is 350 kg. What is it's Moment Of Inertia?
 $Hint\ -\ It's\ most\ like\ a\ disc,\ so\ I\ =\ \frac{1}{2}mr^2$   

• 100 kg

• 324 kg*m

• 141.75 kg*m

• 141.75 m