Consider the three items that are not relevant to the giant impact hypothesis. the lack of volcanoes is a result of the moon’s relatively small size. but what explains the other two items — the moon’s synchronous rotation and gradually increasing distance from earth?
(a)-synchronous rotation is simply a coincidence, and this coincidence in turn causes the moon to move farther away with time.
(b)-both are results of tidal interactions between the moon and earth.
(c)-the giant impact would have caused the moon to rotate synchronously, and the outward fling from the impact would explain the increasing distance.
(d)-both are results of the moon’s small size.

What happens to light waves from a star as the star moves away from earth?

20. threshold braking in the vehicle's braking system occurs when a. the brake pedal is pushed, heel on floorboard, with full foot pressure. b. the brakes are exerting full braking power, without traction loss. c. the driver begins pushing down the brake pedal, with moderate slowdown. d. the brakes just begin to take hold with a gradual slowdown.

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.