Physics

Problem

An object is projected vertically upward from ground with speed

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

. Taking upward direction as positive and

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

, calculate (i) its speed when it is

25\,\text{m}

above the point of projection, and (ii) the time taken to reach this height.