(a(i))[1]
State the name of the force responsible for keeping the Earth in orbit around the Sun.
(a(ii))[1]
State the time needed for the Earth to complete one orbit of the Sun. Include the unit.
(a(iii))[1]
State the time taken by the Earth to rotate once about its axis. Include the unit.
(a(iv))[2]
The Sun is made mainly of two gases. State the names of these two gases.
(b(i))[1]
State the name of one of those other two regions.
(b(ii))[3]
Calculate the time needed for visible light to move from the Sun to the Earth when the Earth is in the position shown in Fig. 11.1.