A race car completes the final lap of a race on a 2-kilometer circular track. At the start of the lap, it crosses the line at 60 meters/second. It completes the lap 28. 57 seconds later, crossing the line at 85 meters/second. Calculate the displacement and average acceleration of the car along the track over the course of the final lap. A. Displacement is 0 meters, and acceleration is 0. 88 meters/second2. B. Displacement is 2,000 meters, and acceleration is 1. 14 meters/second2. C. Displacement is 0 meters, and acceleration is 70. 0 meters/second2. D. Displacement is 2,000 meters, and acceleration is 80. 0 meters/second2. E. Displacement is 0 meters, and acceleration is 0. 70 meters/second2.

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.