An observatory records one spectral line from two distant galaxies. The same line produced by the same element in a laboratory has a wavelength of 620 nm. The measured wavelengths are shown in the table.
| Source | Wavelength of spectral line |
|---|---|
| Laboratory | 620 nm |
| Galaxy A | 651 nm |
| Galaxy B | 682 nm |
Calculate the increase in wavelength for the light from each galaxy.
Compare the recession speeds of galaxies A and B. Explain your answer.
79 exam-style questions on AQA GCSE Physics 8.2 Red-shift, covering 8.2 Red-shift. Each one has a worked solution and a mark scheme showing where the marks go.