MCQ Solution: Motion of System of Particles and Rigid Body
A particle is confined to move in circular path with decreasing speed. Which of the following is correct.
(1)Angular momentum is constant
(2) Only the direction of L is constant
(3) Acceleration is always directed towards the centre
(4) Particle moves in spiral path.
Solution
Angular momentum is an axial vector, so its direction is perpendicular to plane of motion which is not going to change because of change in speed. So only its direction remains same but its magnitude will vary.