Answer: 15.68ms
Explanation:
From the question, we are informed that it takes a time of 3.20s for the ball to return to her hand.
Then, the time thst will be taken by the ball to reach maximum height will be 1.6s
Let the initial speed be represented by v.
Therefore,
Vf = v - gt
where,
g = 9.8
t = 1.6
Vf = v - gt
0 = v - (9.8 × 1.6)
0 = v - 15.68
v = 15.68ms
=v−gt
⟹0=v−9.8×1.6
⟹v=15.68ms
