SAT Subject Physics Practice Question 339: Answer and Explanation
35. When does an artificial earth satellite that is in an elliptical orbit experience its greatest centripetal acceleration?
A. When it first enters orbit
B. When it is nearest the earth
C. When it is farthest from the earth
D. When it leaves orbit
E. Its centripetal acceleration is always the same
Correct Answer: B
The correct answer is (B). The satellite travels at essentially the same velocity in its orbit, although its speed does increase at its closest approach to the earth. The distance from the satellite to the earth also changes while the satellite orbits the earth. The closer approach to the earth decreases the radius of the orbit, which in turn causes an increase in the centripetal acceleration.