Question

what are cases when velocity is zero and acceleration is non zero​

Answer 1

AnswEr:-

Consider a simple example when we start a vehicle, initially we have zero velocity but have non zero acceleration ( that is why vehicle will start moving).

If we drop a ball from some height above the Earth surface the velocity at that instant is zero but acceleration is non zero(gravity) which acts downward.

Answer 2

Explanation:

When a body is projected in the upward direction, at the maximum height, the velocity of the body is zero but the acceleration is towards the surface of the earth.