Here's why:
* During the jump: When you jump, you push off the ground, giving you an upward velocity.
* As you rise: Gravity acts against your upward motion, slowing you down.
* At the highest point: For a brief instant, your upward velocity becomes zero. At this exact moment, gravity is still acting on you, pulling you back down.
* The fall: After this point, gravity causes you to accelerate downwards, increasing your velocity.
Important Note: We're assuming air resistance is negligible for simplicity. In reality, air resistance would slightly oppose your motion both going up and coming down.
