Two protons are released from rest, one from location $1$ and another from location $2.$ When these two protons reach location $3,$ the first proton has a speed that is $2$ times the speed of the second proton. If the electric potentials at locations $1$ and $2$ are $231$ V and $115$ V$,$ respectively, what is the electric potential at location $3?$and $115V,$ respectively, what is the electric potential at location $3?$