1. In Einstein's photoelectric experiment, the kinetic energy (K.E.) of an electron displaced from a metal by a photon was the difference between the energy of a photon and a threshold energy value for the metal. If you were to perform a similar experiment with lead, which has a threshold energy of 6.81 10 J, and ultraviolet light of wavelength 51.9 nm, what would be the speed (v) of the dislodged electron in meters per second? (K.E. = 1/2mv. The mass of the electron = 9.109 10 kg.)