A ball is thrown vertically upward from ground level with a speed of

PHYSICS · Multi-part · CBSE · Physics · Gravitation · Gravitation

Problem

30\,\text{m s}^{-1}

. Take

g = 9.8\,\text{m s}^{-2}

. (a) Calculate the two instants when the ball is exactly

20\,\text{m}

above the ground. (b) Find the time interval between these two instants.