a) In a quark model of elementary particles, a neutron is made of one up quarks and two down quarks. Assume that they have a triangle configuration with a side length of the order of m. Calculate the electrostatic potential energy of the neutron and compare it with its mass 939 MeV.
There are three charges in the system. The potential energy of the system is equal to the sum of the PE of each pair.
Substituting the values we get,