Once the parachute is opened, the air resistance overwhelms the downward force of gravity. The net force and the acceleration on the falling skydiver is upward. An upward net force on a downward falling object would cause that object to slow down. The skydiver thus slows down.

Just before a falling body attains terminal velocity, there is still a downward acceleration since gravitational force is still greater than air resistance. When the air resistance builds up to equal the gravitational force, terminal velocity is reached. Then air resistance is equal and opposite to gravitational force.

Immediately on leaving the aircraft, the skydiver accelerates downwards due to the force of gravity. There is no air resistance acting in the upwards direction, and there is a resultant force acting downwards. The skydiver accelerates towards the ground.

With air resistance, acceleration throughout a fall gets less than gravity (g) because air resistance affects the movement of the falling object by slowing it down. Usually, resistance is not very high at low speed or for small or sharp objects.

A hammer and a feather will fall with the same constant acceleration if air resistance is considered negligible. This is a general characteristic of gravity not unique to Earth, as astronaut David R. In the real world, air resistance can cause a lighter object to fall slower than a heavier object of the same size.

If an object is dropped from a height and there is no air resistance its speed will increase.

Gravity causes objects to fall toward the center of Earth. They all have the same acceleration when acted on by gravitational forces. Why doesn’t a feather fall at the same rate as an apple? Air resistance reduces an object’s downward acceleration and affects objects differently.