Q1 · 2022 · Paper 2Simple familiar2 marks
QUESTION 1 (2 marks)
Two spaceports are stationary relative to each other. Astronaut A moves from one spaceport to the other at relativistic speed and observes the lights on both spaceports turn off at the same time. Astronaut B is at a stationary position equally distant relative to each spaceport and observes the lights turn off one after the other. Explain why the astronauts view these events differently.
WORKED SOLUTION
2 marksQCAA guide · typeset solution
ANSWER
See worked solution below.
Worked solution
For astronaut A to observe simultaneity, light from the first
spaceport will need to travel further than light from the second
spaceport. However, two events can only happen
spontaneously in one inertial frame of reference, and therefore
Astronaut B loses simultaneity in this instance.
• explains simultaneity from the perspective of
astronaut A [1 mark]
• explains the loss of simultaneity for astronaut B
[1 mark]
One QCAA sample method typeset for web; criterion wording is adapted from the official marking guide.
How many marks did you earn?
Compare your working with the guide above.