A color television tube generates some X-rays when its electron beam strikes the screen. What is the shortest wavelength of these X-rays, in meters, if a 31 kV potential is used to accelerate the electrons? (Note that TVs have shielding to prevent these X-rays from reaching viewers.)

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

Which articulations allow for greatest range of motion?

In science and physics what is the standard unit of measure for speed?