Apolice car waits in hiding slightly off the highway. a speeding car is spotted by the police car traveling at speed s = 27.6 m/s. at the instant the speeding car passes the police car, the police car accelerates forward from rest at a constant rate of a = 2.16 m/s^2 to catch the speeding car. assume the speeding car maintains its speed. write an expression for the time it takes the police car to reach the speeding car. use the variables from the problem statement in your expression.

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.