A falling skydiver opens his parachute. A short time later, the weight of the skydiver-parachute system and the drag force exerted on the system are equal in magnitude. Which of the following statements predicts the motion of the skydiver at this time? a. The skydiver is at rest. b. A The skydiver is moving downward with constant speed. c. The skydiver is moving downward with an upward acceleration. d. The skydiver is moving downward with a downward acceleration.

A falling skydiver opens his parachute. A short time later, the weight of the skydiver-parachute system and the drag force exerted on the system are equal in magnitude. The following statements predicts the motion of the skydiver at this time

The skydiver is moving downward with constant speed.

Explanation:

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.

The forces acting on a falling leaf are : gravity and air resistance.

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.

As the speed decreases, the amount of air resistance also decreases until once more the skydiver reaches a terminal velocity.

A skydiver falling at a constant speed opens his parachute. When the skydiver is falling, the forces are unbalanced.

The drag force opposes the relative motion of an object in a fluid

The option that gives the statement that predicts the motion of the skydiver when the magnitude of the weight of the skydiver-parachute system and the drag force are equal is option b.

b. The skydiver is moving downward with constant speed

The reason the above option is correct is as follows:

The skydiver is falling through the air which is a fluid and is therefore subject to drag force, , which is given as follows;

Where;

= The drag force

ρ = The fluid density

v = The relative object speed compared to the fluid

A = Cross sectional area

= The drag coefficient

Therefore, given that the surface area of the falling skydiver is largely increased when the parachute is opened and the drag force is a function of the square of the velocity, we have that the drag force rapidly equals the weight of the skydiver, such that the net force becomes zero, and therefore, the speed of the skydiver becomes constant

Therefore, the correct option is that the skydiver is moving downward with constant speed

Learn more about drag force here:

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from wikipedia