A weightlifter must exert 25 Newtons of force to lift a set of barbells 2 meters off the ground.
How much work did he do on the barbells when he lifted
them?

A. 50 Nm
B. 2.5 Nm
C. 0 Nm

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?