| Date | November 2017 | Marks available | 1 | Reference code | 17N.3.SL.TZ0.13 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 0 |
| Command term | Outline | Question number | 13 | Adapted from | N/A |
Question
The collision of two galaxies is being studied. The wavelength of a particular spectral line from the galaxy measured from Earth is 116.04 nm. The spectral line when measured from a source on Earth is 115.00 nm.
Outline one reason for the difference in wavelength.
[1]
a.
Determine the velocity of the galaxy relative to Earth.
[2]
b.
Markscheme
galaxies are moving away
OR
space «between galaxies» is expanding
Do not accept just red-shift
a.
«\(\frac{{\Delta \lambda }}{\lambda } = \)» \(\frac{{1.04}}{{115}} = \frac{v}{c}\)
0.009c
Accept 2.7×106 «m s–1»
Award [0] if 116 is used for \(\lambda \)
b.
Examiners report
[N/A]
a.
[N/A]
b.
