Enormous Object In Va Pics Is It Just Me Or Does This Seem A Bit Paradoxical. Throw An Object In The Air, It Comes Back, Fnet=0?

Is it just me or does this seem a bit paradoxical. Throw an object in the air, it comes back, Fnet=0? - enormous object in va pics

Use force to interrogate an object in the air, the force of gravity? back, and now seems to have no power to subject the object. Want a man prove himself a huge rock of one hour, until the muscles, to say that because they do not encourage, not fnet Rock = 0 Trust me, I have a force is exerted. I can understand how the work was not finished, by definition, but I fear that the force is not properly labeled zero. And to try, cover labeled "Internet" I think the laziness of scientists who can not define what we call this force gravity.
So miracle is that the mass is a property of gravity or gravity is a property of mass?