ROTATIONAL MOTION

In the expression for angular momentum, what does OM = r sinθ represent?

• The magnitude of velocity
• The time taken to reach point P
• The perpendicular distance from O to the line of velocity
• The angular speed of the particle

Which of the following best describes the angular momentum of a particle about a point O?

• l = r + mv
• l = r × mv
• l = mv/r
• l = r – mv

What is the main conclusion from Eq. (6.28b)?

• Internal forces dominate
• Torque is always zero
• External torque determines the rate of change of angular momentum
• Angular momentum is always increasing

How does the angular momentum of a system change when only internal forces act?

• It increases
• It decreases
• It oscillates
• It does not change

How does the total angular momentum behave in the absence of external torques?

• It gradually decreases
• It changes direction randomly
• It remains constant in magnitude and direction
• It becomes aligned with gravity