As you stand by the side of the road, a car approaches you at a constant speed, sounding its horn, and you hear a frequency of 76 hz. after the car goes by, you hear a frequency of 65 hz. what is the speed of the car? the speed of sound in the air is 343 m/s.

Glass is transparent to visibile light under normal conditions; however, at extremely high intensities, glass will absorb most of the light incident upon it. this works through a process known as multiphoton absorption. in this process, several photons are absorbed at the same time. if very intense light whose photons carry 2ev of energy is shined onto a material with a band gap of 4ev, that light can be absorbed through two-photon absorption, because two photons have the right amount of energy to bridge the band gap. what is the minimum number of photons of 800-nm light that are needed to equal or exceed the band gap of fused silica glass

This is the substance(s) formed in a chemical reaction.

The least penetrating form of radiation is