Question Detail
Question
The time derivative of angular momentum dL/dt for a particle is equal to which physical quantity?
Correct Answer
Option C is the correct answer.
Detailed Explanation
Starting from L = r × p, taking the time derivative gives dL/dt = (dr/dt) × p + r × (dp/dt) = v × (m v) + r × F = 0 + r × F. The term r × F is the definition of torque τ. Therefore, the rate of change of angular momentum of a particle is equal to the net torque acting on it.
Hint
This relationship is the rotational analogue of Newton's second law, F = dp/dt.