Engineers are looking for a new material to build the body of an airplane. they agree that the material must be lightweight, but also strong and long-lasting. above all, the material must maximize the safety of the passengers. several engineers have developed some initial plans. which stage of technological design does this passage describe? identify a problem. design a solution. implement a solution. evaluate the solution.

The nuclear potential that binds protons and neutrons in the nucleus of an atom is often approximated by a square well. imagine a proton conned in an innite square well of length 105 nm, a typical nuclear diameter. calculate the wavelength and energy associated with the photon that is emitted when the proton undergoes a transition from the rst excited state (n 2) to the ground state (n 1). in what region of the electromagnetic spectrum does this wavelength belong?