The Earth may be considered to be a sphere of radius 6.4 10^6 m with its mass of 6.0 10^24 kg concentrated at its centre. A satellite of mass 650 kg is to be launched from the Equator and put into geostationary orbit a) Show that the radius of the geostationary orbit is 4.2 10^7m. [3] b) Determine the increase in gravitational potential energy of the satellite during its launch from the Earth's surface to the geostationary orbit. [3] c) Suggest one advantage of launching satellites from the Equator in the direction of rotation of the Earth [2]​