1
C
2
A
M3.(a)
(i) Spectral line
moved to longer wavelength position (allow ‘to red end of spectrum’)
B1
(ii) Mention
of Doppler effect
B1
Expansion of
universe / Big Bang
B1
Wavelength
increased (or frequency decreased)
B1
Successive
‘peaks’ of wave emitted at increasing distance
from Earth [allow ‘wave stretched’]
from Earth [allow ‘wave stretched’]
B1
Wavelength
observed on Earth increases compared with
source stationary
source stationary
B1
max 4
the use of
physics terms is accurate, the answer is fluent / well argued with few errors
in spelling, punctuation and grammar
B2
award for 2+
the use of physics terms is accurate, but the answer lacks coherence or the spelling, punctuation and grammar are poor
the use of physics terms is accurate, but the answer lacks coherence or the spelling, punctuation and grammar are poor
B1
award for 1
the use of physics terms is inaccurate, and the answer is disjointed with significant errors in spelling, punctuation max 2and grammar
the use of physics terms is inaccurate, and the answer is disjointed with significant errors in spelling, punctuation max 2and grammar
B0
max 2
V = c * Δf / f [or Δλ / λ] = 3 × 108 × 2.08 × 1013 / 5.556 × 1014
C1
[ecf from bi]
M1
= 1.12 × 107 m / s
A1
(iii) [d = v / H]
conversion to km / s
conversion to km / s
C1
d = 11.2 × 103 / 65 = [172 Mpc] [ecf from bii]
B1
= 172 × 106 × 3 × 1016 = 5.17 × 1024 m
A1
[16]
