Hi guys, here's a question from Cambridge 4U EX 7.1 Q9. It is Q9 part (b) where I can not understand what to do.
\textup{The force of attraction experienced by a particle of mass }\, \textit{m}\; \textup{at a distance}\, \textit{x}(>r)\, \textup{from the centre O of the earth towards O is}\...