How would one go about calculating the escape velocity of an object with mass m from the center of the Earth. I understand that that when launched from the surface of the Earth, mechanical energy is conserved and you end up with v escape =sqrt[2gRe] So what i did was i calculated what i thought was the velocitiy it takes to get from the center of the earth to the surface of the Earth and then add the escape velocity from the surface of the Earth to that. I then got 2sqrt[2gRe)]. Is this right? Can someone put me on the right track?