When you post a multiple-choice question, you're expected to
post the choices too.
If the "endocrine system" is on your list, I think it's the best choice
for an answer. If it'd not, then I can't help you, because you won't
let me see what's on the list.
Answer:
Vertical velocity decreases.
Explanation:
The motion of the ball is a projectile ball, which consists of two independent motions:
- a horizontal motion, with constant velocity
- a vertical motion, with constant acceleration g=9.8 m/s^2 towards the ground
In the vertical motion, there is a constant acceleration directed downward: this means that the vertical velocity decreases as the ball goes higher. In fact, it decreases following the equation
And it decreases until the ball reaches its maximum height, then it starts increasing again.