일반물리학 2 — Relativity: Problem 23

23 An experimenter arranges to trigger two flashbulbs simultaneously, producing a big flash located at the origin of his reference frame and a small flash at \(x = 30.0 \text{ km}\). An observer moving at a speed of \(0.450c\) in the positive direction of \(x\) also views the flashes. (a) What is the time interval between them according to her? (b) Which flash does she say occurs first?