The +80 µC load is placed at x = 0 on the x-axis. A second load of –50 µC is also present on the x-axis at x = 50 cm. What is the electrostatic force acting on a 4.0 µC charge at x = 30 cm?

What is the relationship between the wavelength of a wave and it's energy?

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

The radius of an atom is closest in size to a