Solve
-A Rocket Is Launched from the Top of a Cliff

Multiple Choice

Solve.
-A rocket is launched from the top of a cliff. The height, $\mathrm { s } ( \mathrm { t } )$ , of the rocket after $\mathrm { t }$ seconds is given by the equation $s ( t ) = - 16 t ^ { 2 } + 120 t + 48$ . How long after the rocket is launched will it strike the ground? Round to the nearest tenth of a second, if necessary.

A) $9.3 \mathrm { sec }$
B) $7.9 \mathrm { sec }$
C) $8.3 \mathrm { sec }$
D) $8.7 \mathrm { sec }$