The drawing shows a square, each side of which has a length of l = 0.250 m. two different positive charges q1 and q2 are fixed at the corners of the square. find the electric potential energy of a third charge q3 = -4.00 x 10-9 c placed at corner a and then at corner b.

Materials will have different energies associated with the electrons inside them. this is related to how strongly bound they are by their work function. if we sandwich a material with a very low energy between two materials with a high energy, we create a trap for an electron. if this trap is very narrow in one direction in comparison to the others, this is approximately a 1-dimensional box that confines the electron. what is the lowest energy of an electron in the box if the thinnest direction across the materials is 4.81 nm?