When a skydiver is in free fall before opening the parachute, the primary force acting on him is gravity, which pulls him downward. As he accelerates, the speed of his fall increases, leading to a gradual increase in air resistance (also known as drag) opposing this downward motion. However, during the free fall, air resistance is less than the gravitational force, resulting in the skydiver accelerating toward the ground.
When the skydiver opens the parachute, there is a sudden increase in surface area that significantly enhances air resistance. The parachute captures a large volume of air, which drastically increases the drag force acting against the downward movement. This increase in air resistance occurs almost instantaneously upon deployment.
As a result, the forces acting on the skydiver change:
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Before Opening the Parachute: The skydiver experiences downward gravitational force and gradually increasing air resistance.
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At the Moment of Opening the Parachute: There is a rapid increase in air resistance due to the parachute’s deployment, which can become greater than the gravitational force.
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After the Parachute Opens: The air resistance exceeds the weight of the skydiver, resulting in a deceleration. The skydiver will continue to slow down until a new equilibrium is reached. This equilibrium is known as terminal velocity, where the downward gravitational force balances the upward force of air resistance, allowing the skydiver to descend slowly and steadily.
Overall, the key change in forces is that the air resistance transitions from being less than gravitational force to being greater than or equal to it, leading to deceleration and a more controlled descent until reaching terminal velocity.
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