
London is situated at longitude $0^o$, latitude $52^o$ North
and Cape Town at longitude $18^o$ East, latitude $34^o$
South. Taking the earth to be a sphere with unit radius (and
ultimately scaling by 6367 kilometres for the radius of the
earth) work out coordinates for both places, then find the
angle LOC where L represents London, O the centre of the
earth and C Cape Town. Hence find the distance on the surface
of the earth between the two places. If a plane flies at an
altitude of 6 kilometres and the journey takes 11 hours what
is the average speed?
[You might also like to try the problems
'Over The Pole', which is a little simpler, and
'Flight Path' which is similar to 'Air Routes' but the
method of solution given there is a bit different. ]