I don't know much about the potential difference but I certainly can calculate the energy of the proton from rest to 10% of the speed of light.
Special relativity tells us that "the energy needed to accelerate a particle (with mass) grow super-quadratically when the speed is close to c, and is ∞ when it is c."
Expressed the theory in equation is as follows:
ENERGY = rest mass × speed of light squared / (1−(“percent of speed of light”)squared ) = mc2/(1-("percent of speed of light")2)
Just plug-in the values and you can now have the answer what you are looking for!
