Awoman pushes a 27 kg lawnmower at a steady speed. she exerts a 180 n force in adirection 31 degrees below the horizontal. the acceleration of gravity is 9.8 m/^2find the magnitude of the vertical force this lawnmower exerts on the lawn. answer in units of n.

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?