ROTATIONAL MOTION

Why is angular momentum conservation useful in problem solving?

• It replaces Newton's laws
• It is always true
• It provides a constant of motion when τ_ext = 0
• It calculates energy

What is the basis for separating τ into ext and int parts?

• For convenience only
• Due to measurement error
• Forces on each particle are sum of external and internal
• Because internal forces are negligible

How does the total angular momentum of a system behave under central external forces?

• It is always conserved
• It decreases
• It changes unless torque is zero
• It becomes zero

What is the relationship between angular momentum and linear momentum?

• L = p × r
• L = r + p
• L = r · p
• L = r × p for a single particle

Can a single force produce zero torque?

• No, every force produces torque
• Yes, only if force is zero
• Yes, if it acts along the position vector
• Yes, only in vacuum