Understanding Rotational Dynamics and Moment of Inertia

What is the rotational equivalent of force in translational motion?

• Mass

• Displacement

• Torque

• Velocity

In rotational dynamics, what is analogous to mass in translational motion?

• Angular displacement

• Moment of inertia

• Angular velocity

• Torque

How is the moment of inertia of a complex object determined?

• By adding the torque and angular acceleration

• By dividing the total mass by the radius

• By summing the mass times the square of the radius for each point mass

• By multiplying mass and velocity

Why does an ice skater spin faster when they tuck their arms in?

• They decrease their angular velocity

• They increase their angular displacement

• They decrease their moment of inertia

• They increase their mass

How does the distance from the axis of rotation affect the moment of inertia?

• It increases the moment of inertia

• It decreases the moment of inertia

• It has no effect

• It only affects angular velocity

What happens to the angular velocity of an object if its moment of inertia decreases while conserving angular momentum?

• Angular velocity remains constant

• Angular velocity increases

• Angular velocity decreases

• Angular velocity becomes zero

Which has a greater moment of inertia: a solid sphere or a hollow sphere of the same mass and radius?

• Hollow sphere

• It depends on the material

• Solid sphere

• Both have the same

What is the angular acceleration of a door if a 50.0 N force is applied perpendicularly at 0.80 m from the hinge, given the moment of inertia is 80.0 kg m²?

• 2.0 rad/s²

• 0.25 rad/s²

• 1.0 rad/s²

• 0.5 rad/s²

What is the role of kinetic friction in the operation of disc brakes?

• It has no effect on the wheel's motion

• It maintains the wheel's speed

• It reduces the rotational speed by opposing motion

• It increases the speed of the wheel

What is the formula for the moment of inertia of a solid disc?

• 1/2 m r²

• 1/12 m r²

• 1/3 m r²

• 1/4 m r²