X rays with a wavelength of 71 pm are directed onto a gold foil and eject tightly bound electrons from the gold atoms. The ejected electrons then move in circular paths of radius r in a region of uniform magnetic field B. For the fastest of the ejected electrons, the product Br is equal to 1.88 x 10-4 T ∙ m. Find
(a) The maximum kinetic energy of those electrons and
(b) The work done in removing them from the gold atoms.