Study the image below and answer the question.

The following is the graph between potential energy between nucleons versus the separation between them. It is seen that the potential energy is a minimum at a distance r_o of about 0.8 fm.

For a distance r = 0.4 fm, what can you say about the forces?

The forces are repulsive in nature.

As the distance decreases than the minimum value, the equilibrium distance, the potential increases and the forces are repulsive in nature.