(a)[2]
State what is meant by gravitational potential at a point.
(b(i))[2]
Explain why the gravitational potential at X is negative.
(b(ii))[2]
State an expression, in terms of $\Phi$, for the gravitational potential at Y caused by the planet.
(b(iii))[4]
Complete Table 1.1 with expressions, in terms of some or all of $M$, $R$ and $\Phi$, for the listed quantities for satellites X and Y: gravitational field strength at the satellite due to planet; gravitational potential energy of the satellite.