Exactly how fast should a 100 kg mass move tangentially in order to maintain a perfect circular orbit around Earth at a distance of 6,500,000 meters from the center of the Earth?
I can tell you what the orbital velocity would be at 6500 km from the center of the earth, which is only about 130km above the surface of the Earth. At any rate, at 130 km above the Earth's surface your mass would have to travel at about 28,188 km/hour. I don't know about "tangential velocity". Sorry!.