A rocket coasts in an elliptical orbit about the Earth.To attain escape velocity using the least amount of fuel in a brief firing time,should it fire off at the apogee,or at the perigee? (Hint: Let "Fd = change in KE" guide your thinking. )
A)perigee,where it is closest and fastest
B)apogee,where it is farthest and slowest
C)same either location

Question

Quizplus · Accepted Answer

Firing at the perigee, where the rocket is closest to Earth and moving fastest, maximizes the change in kinetic energy for a given amount of fuel, making it the most efficient point to attain escape velocity.

A Rocket Coasts in an Elliptical Orbit About the Earth