Answer:
It will take 3 seconds.
Explanation:
All we have to do is plug in the values we have to the equation the question gave us.
We know that the initial velocity or v = 48, and that the height we are trying to reach is =, so h = 0. We are solving for t
h = -16t^2 + vt
0 = -16t^2+48t
We can factor out -16t on the right side of the equation
0 = -16t(t-3)
Then using the zero product property, we can say that either -16t is equal to 0 in which case t is equal to 0 or t-3 = 0, in which case t = 3. We know that the ball had to leave the ground, so it couldn't have taken no time at all to come back onto the ground. Therefore, we know that the other solution is correct.