Question

Help?

Answer 1

A boy drops a coin off a 64-foot cliff. If the equation of the height, h, of the coin t seconds after it drops is h = -16t2 + 64, about how many seconds will the coin take to reach the bottom of the cliff?

Answer 2

the question is asking for when the height equals zero or more simply put h=0:

\[0=-16t^2+64\]
\[16t^2 = 64\]
\[4t= \pm 8\]
\[t=\pm2\]
because the answer is looking for a time, a negative answer would not make sense. thus t=2

Answer 3

THANK YOOOOOUUU!!! i actually understand XD