IB Physics HL A 5 14 Hl World Lines and Speed Topic Practice

The space-time diagram shows the coordinate axes (x, c t) of an inertial reference frame S. Two events, P and Q, are plotted.

Events P and Q occur simultaneously in an inertial reference frame $S^{\prime}$. The clocks of S and $S^{\prime}$ are synchronized at $x=x^{\prime}=0$.

Determine the speed of $S^{\prime}$ relative to S.