A spectral line has a wavelength of 600 nm when measured in a laboratory. The same line is measured in light from two galaxies.
The wavelength measured for galaxy A is 612 nm. Galaxy A is 0.3 billion light-years from the Earth. The wavelength measured for galaxy B is 636 nm. Galaxy B is 0.9 billion light-years from the Earth.
Explain what these measurements suggest about the motion of the galaxies and the universe.
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.