ROTATIONAL MOTION

What is the direction of change in Lz when torque is applied?

• Opposite to torque
• Perpendicular to torque
• Random direction
• Same as torque direction

What is the effect of stretching arms on moment of inertia?

• Decreases moment of inertia
• No effect
• Makes it zero
• Increases moment of inertia

In which situation is angular momentum not conserved?

• When no force acts
• When moving in circle
• When external torque is present
• When I is constant

Why doesn't the perpendicular angular momentum change in fixed-axis rotation?

• Because it is always zero
• Because torque is parallel
• Because ω is axial
• Because the axis prevents rotational change in that direction

What is the condition for dLz/dt = τ to hold?

• Linear motion
• Free rotation
• Rotation about a fixed axis
• Translational equilibrium