Answers
PART A: He found the same value of q/m for different cathode materials.
PART B: e*E@Sub{0}*d@DIV{(L+@DIV{d;2});m*v@Sub{0}@Sup{2}}
PART C: @DIV{E@Sub{0};B@Sub{0}}
PART D: 1.69*10@Sup{-4}
PART E: Two off-centered spots in the first phase of the experiment; one centered spot in the second phase of the experiment