John is pushing (horizontally) on a 100 kg bench with a force of 380 Newtons. What is the size of the friction force acting on the bench if the coefficient of static friction is 0.4? Where will the bench be 10 seconds after John starts pushing

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?