Respuesta :

cairde

Answer:

7 seconds

Step-by-step explanation:

y=-16t²+96t+112, where t is time and y is distance above water.

We are looking for t when y=0

-16t²+96t+112=0

t²-6t-7=0

(t-7)(t+1)=0

Either t=7 or t=-1.

Since we cant have negative time, the answer is t=7