PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
Two satellites, A and B, of different masses orbit the same planet in separate circular paths that share an identical orbital radius r measured from the planet’s center. Assume each satellite’s mass is negligible compared with the planet’s mass.
(1) Explain why the orbital speed is the same for both satellites even though their masses are different.
(2) Satellite A has twice the mass of satellite B. Compare the magnitudes of the gravitational forces exerted on the two satellites by the planet and justify your answer.
(3) Compare the kinetic energies of satellites A and B. State which is larger and support your conclusion with appropriate reasoning.
(4) Describe how the total mechanical energy of either satellite would change, if at all, were the orbit changed from circular to elliptical while keeping the closest approach to the planet equal to r. Provide a brief justification.