Hi, here we go:
2. A satellite orbits the Earth in a circular orbit. An astronaut on board perturbs the orbit slightly by briefly firing a control jet aimed toward the Earth’s center. Afterward, which of the following is true of the satellite’s path?
(A) It is a ellipse.
(B) It is a hyperbola.
(C) It is a circle with larger radius.
(D) It is a spiral with increasing radius.
(E) It exhibits many radial oscillations per revolution.
Why is it (A) ? in particular, if we imagined the "brief firing" as infinitismal
and causing the actual path to be deviated by ds (where ds is perpindicular
to the tangent of the circle), then we could see that the path will remain
circular with either a larger radius or a smaller one, depending on the
direction of the jet.