Here's why:
* Terminal velocity is the constant speed that a freely falling object eventually reaches when the force of air resistance equals the force of gravity.
* Acceleration is the rate of change of velocity.
* Since the object is moving at a constant speed (terminal velocity), its velocity isn't changing, meaning its acceleration is zero.
Think of it like this: when you jump out of a plane, you start accelerating downwards due to gravity. As you speed up, the air resistance pushing against you increases. Eventually, the air resistance becomes equal to your weight (the force of gravity), and you stop accelerating. This is terminal velocity.
