Find the eelectric force btween two protons separated bya distance of 1 fermi (1fermi=10−15) the protons in a nucleus remain at a separation of this order.
Charge on each proton =1.6×10−19 coulomb
Distance between the charges =10−15m
Fe=14πϵ0q2r2=9×109×(1.6×10−19)2(10−15)2=230N