For a step potential function, assume that the potential barrier at x = 0 is three times as large as the total energy of an incident electron, whose velocity is 1 km/s at x < 0. The mass of electron is 9×10-31 kg. (a). calculate the penetration depth d of the electron impinging on the potential barrier. (b). calculate the probability of finding the electron at a distance of (l=10nm) into the potential barrier.

Four point charges each having charge q are located at the corners of a square having sides of length a. find symbolic expressions for the following. (a) the total electric potential at the center of the square due to the four charges (use any variable or symbol stated above along with the following as necessary: ke.) vtotal= (b) the work required to bring a fifth charge p from infinity to the center of the square (use any variable or symbol stated above along with the following as necessary: w=

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?

How do cracks affect the rate of weathering?