(a) Calculate the change in entropy of a block of copper at 25 8C that absorbs 65 J of energy from a heater. (b) If the block of copper is at 100. 8C and it absorbs 65 J of energy from the heater, what is its entropy change? (c) Explain any difference in entropy change.

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.

Which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?

Which of the following is not associated with mechanical energy? a. motion b. position c. density d. shape