ROTATIONAL MOTION

What happens to rotational kinetic energy when a person pulls arms in while rotating?

• It decreases
• It remains constant
• It becomes zero
• It increases

What is the general law corresponding to Eq. (6.44) for systems of particles?

• Conservation of energy
• Newton’s third law
• Conservation of linear momentum
• Conservation of angular momentum

How is angular momentum conservation demonstrated in Fig. 6.32(a)?

• By applying foot force
• By changing chair height
• By changing arm position to alter rotational speed
• By using weights

What is the consequence of dL⊥/dt = 0 in rotational motion?

• Rotation accelerates
• Torque is zero
• No change in perpendicular angular momentum
• Friction is absent

In the absence of external torque, what remains unchanged in a rotating system?

• Only I
• Only ω
• The product of I and ω
• Kinetic energy