T. 1.1.1.3.4.1.5
Activity A:
Get the Gizmo ready:
• Click the red Reset button on the stopwatch.
• Be sure the Number of points is 2.
Runner position
In the Gizmo, run the "race" many times with a variety of different graphs. (The red points on the graph can be
dragged vertically.) Pay attention to what the graph tells you about the runner.
1. If a distance-time graph contains the point (4, 15), what does that tell you about the runner? (Be specific,
and answer in a complete sentence.)
2. Look at the graph to the right. Notice where the green probe is. If you could see 1
the runner and the stopwatch at this moment, what would you see?

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.