The Sun is a main sequence star.
The Sun will spend a total of about 10 billion years on the main sequence.
The Sun is now 4.6 billion years old.
Calculate how many more years the Sun will spend on the main sequence.
Calculate the percentage of its time on the main sequence that the Sun has already completed.
Scientists use a simple model of the time a star spends on the main sequence.
In the model:
time on main sequence=mass of hydrogen available÷rate at which hydrogen is used\text{time on main sequence} = \text{mass of hydrogen available} \div \text{rate at which hydrogen is used}time on main sequence=mass of hydrogen available÷rate at which hydrogen is used
Star X has 20 times as much hydrogen as the Sun.
Star X uses hydrogen 8000 times faster than the Sun.
Use the model to calculate the time that star X spends on the main sequence.
Star X has more hydrogen than the Sun.
Explain why star X spends less time on the main sequence than the Sun.
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.