A mass has a charge of q = 3e, where e is the charge on an electron. (a) Determine the electric potential (in V) due to the charge at a distance r = 0.220 cm from the charge. (b) Determine the electric potential difference (in V) between a point that is 3r away and this point, that is V(3r) - V(r). (c) Determine the electric potential difference (in V) between a point that is - away and this point, that is - V(r). V (d) How would the answers change if the electrons are replaced by protons? O The sign of answer (a) would change. O The sign of answer (b) would change. O The sign of answer (c) would change. O The sign of all answers would change. O All answers would remain the same.