You could try the "Spinning Bucket" or the "Center Of Gravity" experiment. There are plenty more that you could research! Hope this helped :)
Potential energy is energy that is found in a system, grounded on the position of objects. The Coulomb (C) is the unit of charge, and the unit of electric potential is the Volt (V), which is equivalent to (J/C) or Joule per Coulomb.So the formula for this is potential = kQ / d, plugging in the given from the questions will give us:potential = 8.99e9N·m²/C² * 1.602e-19C / 0.053e-9m = 27 V
