Q22 · 2022 · Paper 1Simple familiar2 marks
QUESTION 22 (2 marks)
A collection of mesons was observed by a detector to move an average distance of 11.0 m when travelling at 95% of the speed of light. However, based on their properties, the mesons were expected to travel an average distance of 3.4 m. Explain the difference between the observed and expected average distances.
WORKED SOLUTION
2 marksQCAA guide · typeset solution
ANSWER
See worked solution below.
Worked solution
The relativistic speed of the mesons indicates they
experience time dilation relative to the observed time over
the distance travelled. This means the mesons appear to
travel for a longer period of time and hence cover a larger
distance.
• identifies that an object at relativistic speed
experiences time dilation [1 mark]
• explains the relationship between time travelled
and observed distance [1 mark]
One QCAA sample method typeset for web; criterion wording is adapted from the official marking guide.
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