The height (in metres) of a ball thrown upwards after seconds is given by

MATHEMATICS · Single correct · CBSE · Mathematics · Quadratic Equations · Quadratic Equations

Problem

The height

h

(in metres) of a ball thrown upwards after

t

seconds is given by

h(t)=-4t^{2}+8t

. At what time(s) does the ball reach the ground? (a)

t=0\,\text{s} \text{ and } t=4\,\text{s}

(b)

t=0\,\text{s} \text{ and } t=\sqrt{2}\,\text{s}

(c)

t=0\,\text{s} \text{ and } t=2\,\text{s}

(d)

t=1\,\text{s} \text{ and } t=2\,\text{s}