Question

A ball is falling through the air. When does it reach terminal velocity?

Answer 1

It reaches terminal velocity when the force of gravity equals the air resistance also known as drag and acceleration becomes constant; a=0

Answer 2

When it accelerates at 8 m/s^2
When the drag force is greater that the gravitational force.
When the force of air resistance is equal to the force of gravity

Answer 3

When the gravitational force no longer acts on the ball