Question: "The moon revolves around the Earth. Is the Moon's linear momentum p constant?(the p is supposed to be in italics and with an arrow over it pointing to the right. It's kinetic energy constant? Assume the orbit is circular." Being this a concept question and not a math question im having some trouble visualizing this problem. What exacly should I consider in order to formulate a good explanation? Any help will be STRONGLY appreciated since I have no physics background whatsoever.