Which statement best explains why the kinetic energy of a satellite increases as it…
PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
Which statement best explains why the kinetic energy of a satellite increases as it approaches perigee in an elliptical orbit around a planet?
(a) The stronger gravitational force near the planet acts tangentially, adding energy to the satellite and increasing its kinetic energy.
(b) Conservation of linear momentum requires the satellite’s speed to rise whenever its orbital radius decreases.
(c) Its gravitational potential energy becomes more negative, so to keep the total mechanical energy constant, the kinetic energy must increase.
(d) Because a smaller radius demands a larger centripetal acceleration (ac=v2/r), the satellite must move faster, raising its kinetic energy.