I read that the satellites donnot have to use their fuel to remain in orbit as they need no do any work against gravity, which is doing 0 work on the satellite. Well, according to he equation $W=F.d $, we get an answer i.e if the angle is 90, $W=0$.
This does not make sense to me. It is a human defined concept and nature does not work according to whatever we say. WHAT does really happen, so that the satellites won’t use their fuel to circle around the earth?