A sound wave traveling through dry air has a frequency of 16 Hz, a wavelength of 22 m, and a speed of 350 m/s. When the sound wave passes through a cloud of nitrous oxide, its wavelength changes to 16 m, while its frequency remains the same. What is its new speed? (The equation for the speed of a wave is v= f x 1.) A. 350 m/s
B. 16 m/s
C. 5,600 m/s
D. 256 m/s

What is the fate of the electrons that interact with a specimen in an electron microscope?

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.

14. a body is projected with velocity vi from a.at the same time another body is projectedvertically upwards from point b withvelocity v2 lies vertically below the highestpoint. both the bodies collide thenv2÷v1is