An (imaginary) train moves along a track at velocity v. Bionica walks down the aisle of the train with velocity u in the direction of the train’s motion. Compute the velocity w of Bionica relative to the ground using the laws of both Galileo and Einstein in the following cases.

(a) v = 500 m/s and u = 10 m/s. Is your calculator accurate enough to detect the difference between the two laws?
(b) v = 107 m/s and u = 10⁶ m/s.