Here's why:

* Initially: When the skydiver jumps out of the plane, they accelerate due to gravity. Their speed increases rapidly.

* Air Resistance Builds: As the skydiver's speed increases, the air resistance (drag) acting against them also increases.

* Terminal Velocity Reached: Eventually, the force of air resistance becomes equal to the force of gravity pulling the skydiver down. At this point, the skydiver stops accelerating and falls at a constant speed – this is their terminal velocity.

Key points:

* Terminal velocity is different for different objects due to factors like shape, weight, and air resistance.

* A skydiver's terminal velocity is around 120 mph (193 km/h) in a freefall position.

* By changing their body position (spreading arms and legs), skydivers can increase their air resistance and reduce their terminal velocity.

Let me know if you'd like to know more about terminal velocity!