5. 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 t is given by h = –16t2 + 156t + 105. When will the rocket hit the ground after it is launched? Round to the nearest tenth of a second. (1 point)
4.9 s
9.8 s
0.6 s
10.4 s

Question

5.   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 t is given by h = –16t2 + 156t + 105. When will the rocket hit the ground after it is launched? Round to the nearest tenth of a second.  (1 point)
4.9 s
9.8 s
0.6 s
10.4 s

anonymous · Answer

$$h = –16t^2 + 156t + 105$$ hits the ground when h = 0 solve 
$$0 = –16t^2 + 156t + 105$$

anonymous · Answer

you need method or just the answer?

anonymous · Answer

i get 10.38 rounded, or 10.4

anonymous · Answer

this is an old one

anonymous · Answer

@satellite73 Thank you so much for showing the method for solving this and not just the answer! :)