Which of these is a good example of newton's first law of inertia

a) a ball sits motionless on the ground

b) a ball gathers speed as it rolls downhill

c) a ball accelerates as it falls out of the classroom window

d) a ball slows down after it is kicked through the grass

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?