At terminal velocity, the acceleration of a body due to air resistance is zero. However, the acceleration due to gravity still exists.
Terminal velocity is the constant velocity reached by an object when the drag force due to air resistance equals the gravitational force pulling the object downwards. At this point, the net force on the object becomes zero, resulting in zero acceleration.
Initially, when an object is falling freely under the influence of gravity, it experiences an acceleration due to gravity. This acceleration is typically denoted as "g" and is approximately 9.8 m/s² on Earth.
As the object gains speed and falls faster, the air resistance acting on it also increases. Eventually, the air resistance becomes strong enough to counteract the force of gravity, leading to a net force of zero and resulting in a constant velocity. At this point, the object reaches terminal velocity.
While the net acceleration becomes zero at terminal velocity, the acceleration due to gravity still exists. The gravitational force continues to act on the object, but it is balanced by the opposing force of air resistance, resulting in no further change in velocity.