Asolid disk of mass 3 kg, radius 0.5 m, and initial angular velocity 10 rad/sec is dropped onto an initially stationary second disk having the same radius and twice the mass. the second disk cannot fall, but is free to rotate. the disks stick and rotate together. assume that there are no external torques. find each of the following.
a) the kinetic energy of the first disk before it is dropped
b) the final angular velocity of the combined disks
c) the final kinetic energy of the combined disks

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?