Answer:
Taking gravity to be 9.8m/s2, The velocity is 24.5m/s2.
Taking gravity to be 10m/s2, The velocity is 25m/s2.
Explanation:
According the first formula of motion under the influence of gravity for upward motion, v=u-gt, where v=final velocity, u=initial velocity, and t= time taken.
Here the time taken for the ball to reach the maximum point is half of 5, which is 2.5 seconds.
And v is 0, since at the maximum point gravity slows down the velocity to 0.
Finding the initial velocity,
v=u-gt
0=u-10(2.5)
u=10(2.5)
u=25m/s