1. Four protons, each with a mass m = 1.67 X 10'27 kg and charge q = +6 2 1.6 x 10'19 C, are held xed at the corners of a square of side length d = 1.0 X 1079 m. (a) What is the electric potential at the location of the proton in the upperright corner of the square due to the three protons at the other corners? You may assume that the potential far from these charges (as r > 00) V = 0. (b) If this proton in the upper right corner is released, it is re pelled by the other protons and moves away. What is its speed A 9 a after it moves far away from the other protons? Assume that the : remaining three protons are still held xed at their positions. I (c) After this proton moves offJ the proton in the lowerleft cor d : ner is then released. It too is repelled by the remaining two I protons. How fast is it moving when it is far away from these : two protons? As before, assume that the remaining two protons V are held xed at their positions while this occurs. 4 - - - -d- - - -> (Show all work to receive full credit.)