Two protons $($each with rest mass M$=1\mathrm{.}6710-27$kg$)$are initially moving with equal speeds in opposite directions. The protons continue to exist after a collision that also produces an v$0$particles$.$ The rest mass of the v$0$is m$=9\mathrm{.}7510-28$kg$.($a$)$If the protons and the v$0$are all at rest after the collision, find the initial speed of the protons. $($b$)$What is the kinetic energy of each proton? $($c$)$What is the rest energy of the v$0.$