Free Body Diagrams & Newton's Law Pairs For a 4-Link Chain

[aligass2004]

Homework Statement

I don't have a picture of the diagram, but I'll do my best to describe it. A chain consisting of 4 identical links is hanging by a rope. The question wants to know what the free body diagrams would be for each link. It also wants all of the Newton's third law pairs to be identified, and it wants the rank, from smallest to largest, of the magnitudes of all forces (explaining the reasoning, including how Newton's 2nd and 3rd laws were used).

Homework Equations

The Attempt at a Solution

 

[JoAuSc]

Are you unsure where to start?

 

[m2003]

First, let's define the system in question. The system consists of the 4-link chain and the rope that it is hanging from. We can draw a free body diagram for the entire system, showing the force of gravity acting on the chain and the tension in the rope holding it up.

Next, we can focus on one of the links in the chain. The free body diagram for this link would show the force of gravity acting downwards, the normal force from the link above it, and the tension in the rope pulling upwards.

Now, let's identify the Newton's third law pairs for this link. The force of gravity on the link is the action force, and the normal force from the link above it is the reaction force. Similarly, the tension in the rope pulling upwards is the action force, and the tension in the rope pulling downwards from the link below it is the reaction force.

To rank the magnitudes of the forces, we can use Newton's second law, which states that force is equal to mass times acceleration. Since the links are identical, they all have the same mass. Therefore, the force of gravity and the normal force will be equal in magnitude. The tension in the rope, however, will vary depending on the position of the link in the chain. The link at the top of the chain will experience the least tension, while the link at the bottom will experience the greatest tension. This is because the tension in the rope is responsible for supporting the weight of all the links above it.

In conclusion, the free body diagrams for the 4-link chain would show the force of gravity, normal force, and tension in the rope for each individual link. The Newton's third law pairs would be the force of gravity and normal force, as well as the tension in the rope and the tension from the link below it. The magnitudes of the forces would be equal for the force of gravity and normal force, while the tension in the rope would vary depending on the position of the link in the chain.