A star is 6 light-years6\text{ light-years}6 light-years away from Earth. A space probe is sent to this star and back again at a constant speed of 0.2% of the speed of light.
What is the total time taken for this round-trip journey?
600 years600\text{ years}600 years
3 000 years3\,000\text{ years}3000 years
6 000 years6\,000\text{ years}6000 years
12 000 years12\,000\text{ years}12000 years
104 exam-style questions on CIE IGCSE Physics 6.2 Stars and the Universe, covering 6.2.1 The Sun as a star, 6.2.2a Galaxies and astronomical distances, 6.2.2b The life cycle of a star, 6.2.3a Galaxies and the scale of the Universe, 6.2.3b Redshift, 6.2.3c The Big Bang Theory and cosmic microwave background radiation, and 6.2.3d The Hubble constant and the age of the Universe. Each one has a worked solution and a mark scheme showing where the marks go.