question_answer 19)

Read each statement below carefully and state, with reasons, if it is true or false: (a) The net acceleration of a particle in circular motion is always along the radius of the circle towards the centre. (b) The velocity vector of a particle at a point is always along the tangent to the path of the particle at that point. (c) The acceleration vector of a particle in uniform circular motion averaged over one cycle is a null vector.  

Answer:

(a) False. The net acceleration of a particle in circular motion is towards the centre only if its speed is constant. (b) True. A particle released at any point of its path will always move along the tangent to the path at that point. (c) True. For any two diametrically opposite points on the circumference, the acceleration vectors are equal and opposite. Hence the acceleration vector averaged over one complete cycle is a null vector.