A rocket is launched at t=0 seconds. Its height, in feet, above sea-level, as a function of time,t, is given by

Question

h(t)=-16t^2+112t+480

When does the rocket hit the ground after it is launched?

Answer 1

0 = 16 t^2 - 112 t - 480
0 = t^2 -7 t - 30

0 = (t-10)(t+7)

t = 10

the other root was before it was launched