An object has been thrown straight up into the air. The formula $h = v t - 16 t ^ { 2 }$ gives the height h of the object above the ground after t seconds, when it is thrown upward with an initial velocity v . After how many seconds will an object hit the ground if it is thrown with a velocity of 112 feet per second?
A) $t = 18$ sec
B) $t = 23$ sec
C) $t = 6$ sec
D) $t = 20$ sec
E) $t = 7$ sec

Question

Quizplus · Accepted Answer

The object hits the ground when $h = 0$. Solving $0 = 112t - 16t^2$ gives $t = 0$ or $t = 7$. The object hits the ground at $t = 7$ seconds.

An Object Has Been Thrown Straight Up into the Air h=vt−16t2h = v t - 16 t ^ { 2 }h=vt−16t2

An Object Has Been Thrown Straight Up into the Air $h = v t - 16 t ^ { 2 }$