In a quark model of elementary particles, a neutron is made of one up quark (charge `=2/3e`) and two down quarks (charges `=1/3e`). Assume that they have a triangle configuration with side length of the order of `10^(-15)m.` Calculate electrostatic potential energy of neutron.

Explanation

The electrostatic potential energy of neutron
`u= 1/(4piepsi_0)[((2/3e)(-1/3e))/r + ((2/3e)(-1/3e))/r + ((-1/3e)(-1/3e))/r]`

`1/(4pi epsi_0) (-1/3 e^2/r) = (-9 xx 10^9 xx (1.6 xx 10^(-19))^2)/(3xx (10^(-15)))`
`=-7.68 xx 10^(-14) J = -(7.68 xx 10^(-14))/(1.6 xx 10^(-19)) eV = - 4.8 xx 10^5 eV = - 0.48 MeV`