2. The width of a piece of paper was measured five times using a metre ruler. The acquired measurements are presented below:
Measurement
Width (cm)
31.24
31.15
31.26
31.02
31.20
Calculate the measuring error and give the width of the paper (6 marks)​

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?