A skydiver eventually reaches a terminal velocity after jumping from a plane. This is when the skydiver is moving at a constant speed downward.

Question

Question
Which diagram represents the forces acting on a skydiver of mass m who is moving at a constant speed downward?
Answer options with 4 options
A.
Short description, A diagram.,Long description,
The diagram shows a skydiver. A medium arrow labeled m g points from the bottom of the skydiver directly down.
B.
Short description, A diagram.,Long description,
The diagram shows a skydiver. A long arrow labeled wind resistance points from the top of the skydiver directly up. A short arrow labeled m g points from the bottom of the skydiver directly down.
C.
Short description, A diagram.,Long description,
The diagram shows a skydiver. A short arrow labeled wind resistance points from the top of the skydiver directly up. A medium arrow labeled m g points from the bottom of the skydiver directly down.
D.

Answer 1

To determine which diagram represents the forces acting on a skydiver at terminal velocity, we need to consider the conditions at this point. Terminal velocity occurs when the forces acting on the skydiver are balanced, meaning the downward force of gravity is equal to the upward force of air resistance (or wind resistance).

At terminal velocity:

1. The downward force due to gravity, represented as \( mg \) (mass times acceleration due to gravity), acts downward.
2. The upward force from air resistance acts upward and must be equal in magnitude to the downward force at this point.

Therefore, the correct diagram would show:

• A medium arrow (indicating the force of gravity \( mg \)) pointing down.
• A long arrow (indicating the force of wind resistance/air resistance) pointing up.

Given these considerations, the correct option is:

B. The diagram shows a skydiver. A long arrow labeled wind resistance points from the top of the skydiver directly up. A short arrow labeled \( mg \) points from the bottom of the skydiver directly down.

This option indicates that wind resistance is greater than the weight of the skydiver, which is not correct for terminal velocity. So ultimately, the correct answer should balance these forces, making option C the ideal representation if we consider lengths to show balance explicitly.

However, if we look for an option that explicitly states the forces are equal, B and C may not fit this perfectly because they show different force lengths. Yet C shows a balance wherein traditional notation means the vertical forces are equal at terminal velocity. It’s best to choose C under these considerations, as it maintains accurate size representation generally used for these problems.