Q25 · 2023 · Paper 1Simple familiar3 marks
QUESTION 25 (3 marks)
An observer who is stationary relative to a moving spaceship measures the velocity of the spaceship to be 2.0 × 108 m s-1. Calculate the length of the spaceship if the observer records it as 18 m. Show your working.
WORKED SOLUTION
3 marksQCAA guide · typeset solution
ANSWER
See worked solution below.
Worked solution
Sample response The
2 °re
L =1,ft-% °
c °c
‘i
82
18=1, 1 -G20x10 y ° ce
(3.0x10°) i
I, =24m
Length = 24 m (to two significant figures)
e recognises the scenario relates to an object
experiencing length contraction [1 mark]
e correctly substitutes for relativistic length
[1 mark]
e calculates the length of the spaceship
[1 mark]
One QCAA sample method typeset for web; criterion wording is adapted from the official marking guide.
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