An astronomer compares two massive main sequence stars. Assume that each star uses its available hydrogen at a steady average rate during its main sequence stage.
| Star | Mass (times the mass of the Sun) | Available hydrogen (1030 kg10^{30}\ \text{kg}1030 kg) | Main sequence duration (million years) |
|---|---|---|---|
| P | 10 | 6 | 30 |
| Q | 20 | 12 | 10 |
Explain how the data and the difference in mass support the conclusion that star Q uses hydrogen faster than star P.
75 exam-style questions on Edexcel GCSE Physics 7.3 Stars, covering 7.3.1 Evolution of stars similar to the Sun, 7.3.2 Evolution of massive stars, and 7.3.3 Observing the Universe. Each one has a worked solution and a mark scheme showing where the marks go.