If a parachutist with a mass of 67 kg falls at a constant velocity of 15 m/s, what is the force of air drag acting on the parachute?

To determine the force of air drag acting on the parachutist, we can utilize Newton's first law of motion, which states that an object will maintain its state of motion unless acted upon by a net external force. When the parachutist is falling at a constant velocity, the forces acting on them are in equilibrium. This means the force of air drag must be equal in magnitude to the gravitational force acting on the parachutist.

First, we calculate the weight of the parachutist using the equation:

Weight (force due to gravity) = mass × gravitational acceleration.

In this scenario, the mass of the parachutist is 67 kg, and the acceleration due to gravity is approximately 9.81 m/s² (this value is typically used unless specified otherwise). Therefore, the weight can be calculated as follows:

Weight = 67 kg × 9.81 m/s² = 658.27 N.

Since the parachutist is falling at a constant velocity, the air drag force must be equal to the weight of the parachutist in order to maintain that equilibrium. Thus, the force of air drag is approximately 658.27 N.

When rounding to two significant figures, this correlates closely to the choice