Question

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 1

(i)

The statement "the net acceleration of a particle in circular motion is always along the radius of the circle towards the centre" is false because the net acceleration of a particle in circular motion is not always directed along the radius of the circle toward the centre. It happens only in the case of uniform circular motion.

(ii)

The statement "the velocity vector of a particle at a point is always along the tangent to the path

of the particle at that point" is true because at any point on a circular path, a particle appears to move tangentially to the circular path.

(iii)

The statement "the acceleration vector of a particle in uniform circular motion averaged over one cycle is a null vector" is true, because a particle in uniform circular motion always returns to its starting position after its cycle is over. Hence, the displacement vector is zero and so are the velocity and acceleration vector.