HW3

1. A temperature of 315 K was measured remotely with a pyrometer. Applying Wien's displacement law, what is the corresponding wavelength of the electromagnetic radiation (for which Planck's black body radiation law predicts a maximum in intensity)? 3 points. Is the person that was the subject of the remote measurement sick with a fever? 1 point. What is the energy of 100 photons of this radiation (in eV)? 1 point

2. The wavelength of characteristic X-rays that are used of X-ray crystallography is on the order of magnitude of 0.1 nm. What is the energy (in eV) of 100 photons of this radiation? 5 points