An astronomer analyses the light from a distant galaxy. One of the spectral lines in the observed spectrum from the galaxy has a wavelength of 676 nm676\text{ nm}676 nm. The same spectral line has a wavelength of 656 nm656\text{ nm}656 nm when measured in the laboratory.
What is the speed of this galaxy?
9.1×106 m s−19.1 \times 10^6\text{ m s}^{-1}9.1×106 m s−1
9.4×106 m s−19.4 \times 10^6\text{ m s}^{-1}9.4×106 m s−1
2.9×108 m s−12.9 \times 10^8\text{ m s}^{-1}2.9×108 m s−1
3.0×108 m s−13.0 \times 10^8\text{ m s}^{-1}3.0×108 m s−1
66 exam-style questions on OCR A A Level Physics Astrophysics and cosmology, covering Stars, Electromagnetic radiation from stars, and Cosmology. Each one has a worked solution and a mark scheme showing where the marks go.