Part D : Orbits 1. An object is moving in a circular orbit around the earth with some radius R. Use the Law of Universal Gravitation and Newton's 2 ad Law to determine the object's orbital velocity. 2. Write an expression for the kinetic energy of an object in a circular orbit . Write this in terms of the object's GPE. 3. Write an expression for the total energy of an object in a circular orbit. Write this in terms of the object's GPE. 4. To calculate the energy necessary to move from one situation to another we compare the total energy in each . How much work must be done by a rocket engine to transfer a 1000 kg satellite from an orbit of radius 2R , to 3R,? 5. How much work must be done by a rocket engine to lift a 1000 kg payload from rest on the earth's surface to a circular orbit of radius 2R ? 6. The binding energy is the work that must be done to allow an object to escape to infinity . What is the binding energy for an object : a) on the surface of the earth b) in a circular orbit around the earth