Answer:
Step-by-step explanation:
velocity of projection = vo
angle of projection = θ
When the ball is at maximum height, its vertical component of velocity is zero, So it has only the horizontal component of velocity at highest point.
velocity at highest point = vo Cos θ
The acceleration acting on the ball is only the acceleration due to gravity which always acts vertically downward.
So, teh acceleration of the ball at the highest point is g.