Fig. 9.1 illustrates the Sun and the rest of the Solar System travelling in a circular orbit around the centre of the Milky Way. Diagram labels: Milky Way, orbit about centre, centre of Milky Way, position of Solar System, 26 000 light-years. The Sun moves along this circular path with speed v. The speed of light in a vacuum is $9.5 \times 10^{12}$ km/year. The Sun lies 26 000 light-years from the centre of the Milky Way.
(a(i))[2]
Determine the distance from the Sun to the centre of the Milky Way, in kilometres (km).
(a(ii))[2]
The Sun needs $2.3 \times 10^{8}$ years for a single trip around the centre of the Milky Way. Calculate the speed v.
(b(i))[2]
Astronomical observations indicate that a black hole exists at the centre of the Milky Way. Black holes are formed from red supergiants. Near the end of its life, a massive star becomes a red supergiant. Describe what happens inside the star as it becomes a red supergiant.
(b(ii))[3]
Describe how a red supergiant forms a black hole.
(b(iii))[1]
Describe how the heaviest elements are made.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “9.5 \times 10^12 km \times 26 000, or $2.5 \times 10^17$ km shown” …