Solve the problem.
-If an object is propelled upward from a height of 160 feet at an initial velocity of 144 feet per second, then its height after $t$ seconds is given by the equation $h ( t ) = - 16 t ^ { 2 } + 144 t + 160$. After how many seconds does the object hit the ground?
A) $11 \mathrm { sec }$
B) $5.0 \mathrm { sec }$
C) $9.0 \mathrm { sec }$
D) $10 \mathrm { sec }$

Question

Quizplus · Accepted Answer

To find when the object hits the ground, set $h(t) = 0$ and solve $-16t^2 + 144t + 160 = 0$. Solving this quadratic equation gives $t = 10$ seconds.

Solve the Problem ttt Seconds Is Given by the Equation h(t)=−16t2+144t+160h ( t ) = - 16 t ^ { 2 } + 144 t + 160h(t)=−16t2+144t+160

Solve the Problem $t$ Seconds Is Given by the Equation $h ( t ) = - 16 t ^ { 2 } + 144 t + 160$