Question $16(1$ point$)$

A stone is tossed from a tower $30$ m above the ground. The height of the stone, $h,$ in metres above the ground at $t$ seconds can be modelled by the function $h(t)=-4\mathrm{.}9(t-2{)}^{2}49\mathrm{.}6$

Determine the velocity at $4$ s

$-16\frac{m}{s}$

$-19\mathrm{.}6\frac{m}{s}$

$49\mathrm{.}6\frac{m}{s}$

$30\frac{m}{s}$