IB Physics HL A.5.13 Space-time diagrams Question Bank
Practise IB Physics HL A.5.13 by applying space-time diagrams concepts to exam-style physics questions.
- Syllabus
- First assessment 2025
- Course
- Physics HL
- Level
- HL
Practise IB Physics HL A.5.13 by applying space-time diagrams concepts to exam-style physics questions.
An observer P sitting in a train moving at a speed v measures that his journey takes a time Δtp. An observer Q at rest with respect to the ground measures that the journey takes a time ΔtQ.
According to Q there is an instant at which the train is completely within the tunnel. At that instant two lights at the front and the back of the train are turned on simultaneously according to Q .

The spacetime diagram according to observer Q shows event B (back light turns on) and event F (front light turns on).

Draw the time ct′ and space x′ axes for observer P's reference frame on the spacetime diagram.
axes drawn with correct gradients of 35 for ct′ and 0.6 for x′
Award [1] for one gradient correct and another approximately correct.