Which statement describes how objects can be affected by a noncontact force between then?
O A. An electric force between two objects will always cause them to
attract each other.
B. A gravitational force between Two objects will always cause then
to repel each other.
C. A magnetic force between two objects will always cause them to
attract each other.
D. An electric force between two objects may cause them to either
attract or repel each other.

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?