DP Physics (last assessment 2024)
Question 18M.2.HL.TZ1.c
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.2.HL.TZ1.c |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Explain | Question number | c | Adapted from | N/A |
c.
[Maximum mark: 2]
18M.2.HL.TZ1.c
A beam of coherent monochromatic light from a distant galaxy is used in an optics experiment on Earth.
The wavelength of the light in the beam when emitted by the galaxy was 621.4 nm.
Explain, without further calculation, what can be deduced about the relative motion of the galaxy and the Earth.
[2]
Markscheme
wavelength increases (so frequency decreases) / light is redshifted
galaxy is moving away from Earth
Allow ECF for MP2 (ie wavelength decreases so moving towards).
[2 marks]
