Im not your average flat earther, im alot more intelligent.
Flat earthers would shrug off sattelites as a hologram or a plane. Not the case at all, we can detect sattelites with homemade devices and confirm they are real. But how do they stay up there? Gravity, ofcourse. Now your question is how does gravity work on a flat earth? Let me show you. http://imgur.com/a/4Klsj
The reason flat earthers shrugg of gravity as false information, is because they are uninformed and dont know how to answer. Much like an average man cant answer questions that a sientist can answer.
Lets get started on gravoid. What is the gravoid? Its where sattelites can get into orbit. What causes it is unknown but its real and we observe it. What causes gravity on earth, unknown. I may add that its unknown what causes gravity on the supposed ball earth.
I have also done some tests to find out amazing things about gravity. One of them is that for some odd reason, Gravity is stronger in the round circle of antartica and on the north pole. But on equator its weaker.