Astronomers use the following measurements to estimate distances to galaxies.
| Distance (million light years) | Red-shift (%) |
|---|---|
| 40 | 0.3 |
| 80 | 0.6 |
| 120 | 0.9 |
A galaxy has a red-shift of 1.5%.
Which is the best estimate of the galaxy's distance?
160 million light years
240 million light years
400 million light years
200 million light years
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.