Alever is used to lift a 500 lb weight with a 75 lbf input force. a) calculate the required mechanical advantage b) calculate the required length of l. the angle of the lever with respect to the horizontal is small enough to assume the forces are perpendicular to the lever.

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?