Suppose a wheel with a tire mounted on it is rotating at the constant rate of 2.63 2.63 times a second. A tack is stuck in the tire at a distance of 0.397 m 0.397 m from the rotation axis. Noting that for every rotation the tack travels one circumference, find the tack's tangential speed.

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?