Q17 · 2023 · Paper 1Simple familiar1 mark
QUESTION 17
The half-life of an unstable subatomic particle is measured by a stationary detector to be longer when its velocity approaches the speed of light. This is because the particle
(A)
is moving relative to its frame of reference.
(B)
is in the same frame of reference as the detector.
(C)
experiences time differently relative to the detector.
(D)
cannot be accurately observed at relativistic speeds.
WORKED SOLUTION
1 markAnswer C
ANSWER
C
Worked solution
The detector and particle are in different inertial frames. Time dilation makes the moving particle’s lifetime appear longer to the detector. Option C.
Selects option C.
Worked explanation by QCE Vault; correct option verified against the QCAA answer key.