Solve the Problem $64 \mathrm{ft} / \mathrm{sec}$ , Its Height After $\mathrm{t} \mathrm{sec}$

Multiple Choice

Solve the problem.
-If an object is thrown upward with an initial velocity of $64 \mathrm{ft} / \mathrm{sec}$ , its height after $\mathrm{t} \mathrm{sec}$ is given by $h=64 t-16 t^{2}$ . Find the number of seconds before the object hits the ground.

A) $32 \mathrm{sec}$
B) $2 \mathrm{sec}$
C) $4 \mathrm{sec}$
D) $48 \mathrm{sec}$