The table shows wavelengths for the same spectral line. The laboratory wavelength is 400 nm400\ \mathrm{nm}400 nm.
| Galaxy | Observed wavelength in nm |
|---|---|
| P | 412 |
| Q | 404 |
| R | 408 |
Using the general relationship between red-shift and distance, which gives the galaxies in order from nearest to furthest?
P, R, Q
R, Q, P
Q, P, R
Q, R, P
94 exam-style questions on Edexcel GCSE Physics 7.2 The Universe and red-shift, covering 7.2.1 Big Bang and Steady State theories, 7.2.2 Evidence for the Big Bang, 7.2.3 The Doppler effect and red-shift, 7.2.4 Red-shift as evidence for an expanding Universe, and 7.2.5 The CMB and the accepted model. Each one has a worked solution and a mark scheme showing where the marks go.