In an experiment in space, one proton is held fixed and another proton is released from rest

Question:

In an experiment in space, one proton is held fixed and another proton is released from rest a distance of 2.50 mm away.
(a) What is the initial acceleration of the proton after it is released?
(b) Sketch qualitative (no numbers!) acceleration-time and velocity-time graphs of the released proton's motion.