- The space–time diagram shows the coordinate axes (x, ct) of an inertial reference frame S. Two events, P and Q, are plotted.
(a) (i) Calculate the space–time interval (Δs)² between P and Q. [2]
(ii) (Δs)² is an invariant quantity. Outline what is meant by an invariant quantity. [1]
(Question 7 continued)
Events P and Q occur simultaneously in an inertial reference frame S′. The clocks of S and S′ are synchronized at x = x′ = 0.
(b) (i) Sketch, on the diagram, the coordinate axes (x′, ct′) of S′. [2]
(ii) Determine the speed of S′ relative to S. [1]