Steam at a pressure of 15 bar and a temperature of 320oc is contained in a large vessel. connected to the vessel through a valve is a turbine followed by a small initially evacuated tank with a volume of 0.6 m3. when emergency power is required, the valve is opened and the tank fills with steam until the pressure is 15 bar. the temperature in the tank is then 400oc. the filling process takes place adiabatically and kinetic and potential energy effects are negligible. determine the amount of work developed by the turbine, in kj.

Some material consisting of a collection of microscopic objects is kept at a high temperature. a photon detector capable of detecting photon energies from infrared through ultraviolet observes photons emitted with energies of 0.3 ev, 0.5 ev, 0.8 ev, 2.0ev, 2.5ev, and 2.8ev. these are the only photon energies observed. (a) draw and label a possible energy-level diagram for one of the microscopic objects, which has four bound states. on the diagram, indicate the transitions corresponding to the emitted photons. explain briefly. (b) would a spring–mass model be a good model for these microscopic objects? why or why not? (c) the material is now cooled down to a very low temperature, and the photon detector stops detecting photon emissions. next, a beam of light with a continuous range of energies from infrared through ultraviolet shines on the material, and the photon detector observes the beam of light after it passes through the material. what photon energies in this beam of light are observed to be significantly reduced in intensity (“dark absorption lines”)? explain briefly.