Acar accelerates horizontally from rest on a level road at a constant acceleration of down the road, it passes through two photocells ("electric eyes" designated by 1 for the first one and 2 for the second one) that are separated by 20.0 m. the time interval to travel this 20.0-m distance as measured by the electric eyes is 1.40 as.
(a) calculate the speed of the car as it passes each electric eye.
(b) how far is it from the start to the first electric eye

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?