Aball is released from a tower at a height of 100 meters toward the roof of another tower that is 25 meters high. the horizontal distance between the two towers is 20 meters. with what horizontal velocity should the ball be imparted so that it lands on the rooftop of the second building?

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?