a rocket is launched from atop a 105-foot cliff with an initial velocity of 156 ft/s.The height of the rocket above the ground at time or t is given by h=-16tsquared+156t+105. When will the rocket hit the ground after it is launched?

1 answer

when is h= 0?

0=h(t)=-16t^2 + 156t+105

solve for t.