The height in feet h of a rocket in flight is given by the formula $h = - 16 t ^ { 2 } + 224 t$ , where t is the time of the flight in seconds. How long will it take for the rocket to hit the ground?
A)13 sec
B)14 sec
C)16 sec
D)12 sec
E)11 sec

Question

Quizplus · Accepted Answer

To find when the rocket will hit the ground, we set $h = 0$ and solve for $t$: $0 = -16t^2 + 224t$. Factoring out $16t$, we get $16t(-t + 14) = 0$. This gives $t = 0$ (launch time) and $t = 14$ seconds. Since we're interested in when it hits the ground after launch, the answer is 14 seconds.

The Height in Feet H of a Rocket in Flight h=−16t2+224th = - 16 t ^ { 2 } + 224 th=−16t2+224t

The Height in Feet H of a Rocket in Flight $h = - 16 t ^ { 2 } + 224 t$