An astronomer measures an absorption line in the spectrum of each of two galaxies. A different absorption line is used for each galaxy.
| Galaxy | Laboratory wavelength in nm | Observed wavelength in nm |
|---|---|---|
| K | 486.0 | 500.6 |
| L | 656.0 | 672.4 |
Calculate the fractional increase in wavelength for each galaxy.
Explain which galaxy is expected to be more distant from the Earth.
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.