Moritz is watching his little brother play in a mud puddle. Moritz notices that when his brother stirs it with a stick, after a few moments the dirt settles back to the bottom of the puddle. His brother is creating a .

Anjali knows that whole milk has more fat than skim milk. However, the solid fat doesn’t seem to separate from the liquid milk even after it has been in the fridge for a few days. This is evidence that m

Abearing is designed to a reduce friction b. support a load c. guide moving parts such as wheels, shafts and pivots d. all of the above

Aregular polygon has angkes of size 150° each. how many side has the polygon

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.