Understanding the Delicate Balance Between Forces in Nuclear Physics

[endeavour]

The question is in the attachment..



My thoughts were that between 2 protons, there's obviously going to be higher electrostatic repulsion, so a higher attractive strong force is needed (to keep the protons together), than with 2 nucleons. But the highest strong force is when separation is low, but that's also when the electrostatic repuslion would be great?

 

[OlderDan]

The question is asking about the equilibrium separation. Suppose you had two neutrons in equlibrium (separation $$\displaystyle{x_0}$$), and you could change them into protons. What would happen?

The strong force is called the strong force because it really is strong- way stronger than the electrostatic force. If I am reading the graph correctly, it represents force in units of kiloNewtons as a function of separation. What would the force between two protons be if separted by $$x_0$$? That is a number you can work out.

 

[thepatientmental]

Your thoughts are on the right track. In nuclear physics, there is a delicate balance between the strong nuclear force and the electrostatic force. The strong nuclear force is responsible for holding protons and neutrons together in the nucleus, while the electrostatic force is responsible for the repulsion between positively charged protons.

As you mentioned, the strong force is strongest at very small distances, but at these distances, the electrostatic repulsion is also very strong. This is why larger nuclei tend to be less stable, as the electrostatic repulsion between protons becomes stronger and overcomes the strong nuclear force, causing the nucleus to break apart.

In the case of two protons, the electrostatic repulsion is indeed greater, and therefore a stronger attractive force is needed to keep them together. This is why the strong nuclear force is stronger in smaller nuclei, as it needs to overcome the larger electrostatic repulsion.

Overall, the delicate balance between these two forces is what determines the stability and properties of different nuclei, and it is an important aspect of nuclear physics.