Physics

Problem

A ball is projected vertically upward from the ground. It passes a point

25\,\text{m}

above the ground twice, the two instants being

4\,\text{s}

apart. Ignoring air resistance and taking

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

downward, the initial speed of projection is a)

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

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

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

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