Two protons and two positrons form a square as shown in the figure. All the particles are initially at rest. Due to Coulomb's repulsion, the particles fly off to infinity. Determine the ratio vp/ve where vp and ve are the final velocities of the protons and positrons, respectively. Note that the positron, being electron's antiparticle, has the same mass as the electron and opposite charge (q=+1.6×10^−19C).Details and assumptions
mp/me=1836
Hint: since the protons are so much heavier, you can do this without having to solve momentum conservation.