Observer S detects two flashes of light. A big flash occurs at x1 = 1700 m and, 7.11 μs later, a small flash occurs at x2 = 910 m. As detected by observer S', the two flashes occur at a single coordinate x'.
(a) What is the speed parameter of S', and (b) is S' moving in the positive or negative direction of the x axis? To S', (c) which flash occurs first and (d) what is the time interval between the flashes?