Answer:
Explanation:
Velocity will be zero when the derivative of position is zero.
Set the origin at the ground with UP as the positive direction
The equation with the known information included is
h = -16t² + 112t + 0
h' = -32t + 112
0 = -32t + 112
32t = 112
t = 112/32
t = 3.5 s
