Suggest a way that you and a friend could measure the acceleration due to gravity, using a tennis ball, stopwatch, meter stick, and tape:

1. the procedure you would use,
2. assume and assign some values for the measurements you would make (don’t forget your
units),
3. and calculate what the acceleration due to gravity would be using your assigned values.

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?