Mathematics

Problem

A ball is thrown vertically upward from ground level. Its height (in metres) after

t

seconds is given by

h(t)=-t^{2}+5t+14

. After how many seconds will the ball hit the ground again? a)

5\,\text{s}

2.5\,\text{s}

7\,\text{s}

2\,\text{s}