Use the Position Equation $s = - 16 t ^ { 2 } + v _ { 0 } t + s _ { 0 }$

Multiple Choice

Use the position equation $s = - 16 t ^ { 2 } + v _ { 0 } t + s _ { 0 }$ , where s represents the height of an object (in feet) , $v _ { 0 }$ represents the initial velocity of the object (in feet per second) , $s_0$ represents the initial height of the object (in feet) , and t represents the time (in seconds) . A projectile is fired straight upward from ground level $\left( s _ { 0 } = 0 \right)$ with an initial velocity of 160 feet per second.At what instant will it be back at ground level?

A) $t = 8$ Sec
B) $t = 10$ Sec
C) $t = 12$ Sec
D) $t = 11$ Sec
E) $t = 9$ Sec