you strike a ball of mass 0.113kg coming at you with a speed of 15.2 m/s with a metal rod. it is sent back the way it came at a speed of 10.2 m/s. if the rod makes contact with the ball for 0.312s what is the average force supplied by the rod to the ball when it is in contact with the ball?

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?