Problem
i. Red light of wavelength 620mm ejects electrons from an unknown material with kinetic energy of 0.80eV. What will be the kinetic energy of ejected electrons when photons with 1.602 E-27 kg m/s of momentum hit the unknown material? Hint: Use the data with the red light to find the BE. and use the connection between the photon's momentum and energy.
ii. A spaceship heading toward the Earth at 0.82c (relative to the Earth) shoots a canister at the 0.65c relative to the spaceship toward the earth. If the mass of the canister is 750g. what is the kinetic energy of the canister relative to the Earth? Hint: Find the speed of the canister relative to Earth and don't use 1/2mv^2 for the kinetic energy.
iii. A wavelength of 4.653 um is observed in a hydrogen spectrum for a transition that ends in the nf = 5 level. What was ni, for the initial level of tie electron?