The Earth may be assumed to be an isolated uniform sphere with its mass of 6.0 × 10^24 kg concentrated at its centre. A satellite of mass 1200 kg is in a circular orbit about the Earth in the Earth's gravitational field. The period of the orbit is 94 minutes.

1. (a)Define gravitational field strength.[1]
2. (b)Calculate the radius of the orbit of the satellite. radius = ........................................................... m [3][3]
3. (c)Rockets on the satellite are fired so that the satellite enters a different circular orbit that has a period of 150 minutes. The change in the mass of the satellite may be assumed to be negligible.
4. (c)(i)Show that the radius of the new orbit is 9.4 × 10^6 m.[2]
5. (c)(ii)State, with a reason, whether the gravitational potential energy of the satellite increases or decreases.[1]
6. (c)(iii)Determine the magnitude of the change in the gravitational potential energy of the satellite. change in potential energy = .............................................................. J [3][3]