Question

The man is pushing himself forward with a force of 30 newtons. The net force on the man is 10 newtons forward. What is the parachute doing?

Answer 1

The parachute is providing a drag force of 20 newtons in the opposite direction to the man's motion. This is necessary in order to create a net force of 10 newtons forward on the man. The parachute is essentially slowing down the man's forward motion by creating an opposing force.