Final answer:
The upward force of air resistance acting on a 50 kg parachutist accelerating downward at 2.0 m/s² is approximately 390 N. This is calculated using Newton's second law of motion and by taking into account the gravitational force and the net force acting on the parachutist.
Step-by-step explanation:
The student's question involves the physics concept of forces and motion, specifically relating to a parachutist in free fall and the forces of gravity and air resistance acting on them. To understand the upward force of air resistance acting on the parachutist, we will use Newton's second law of motion which is defined by the equation F = ma, where F is force, m is mass, and a is acceleration.
In this scenario, the parachutist has a mass of 50 kg and an acceleration of 2.0 m/s² in the downward direction. The downward force due to gravity (gravitational force) can be calculated by multiplying the mass of the parachutist by the acceleration due to gravity (9.8 m/s²). This results in a force of 50 kg * 9.8 m/s² = 490 N. Since the parachutist is accelerating downward at 2.0 m/s², the net force acting on the parachutist must be 50 kg * 2.0 m/s² = 100 N downward. Therefore, to achieve this net force while countering the force of gravity, the upward force of air resistance must be 490 N (gravity) - 100 N (net force) = 390 N upward.