Figure 6.72 is a graph of the energy of a system of a planet interacting with a star. The gravitational potential energy Ug is
shown as the thick curve, and plotted along the vertical axis are various values of K + Ug
(B) When the separation between the two bodies is r2, the kinetic energy of the system is (A − B).
(C) The system is a bound system; the planet can never escape.
(D) The planet will escape.
(E) When the separation between the two bodies is r2, the kinetic energy of the system is (B − C).
(F) The kinetic energy of the system is greater when the distance between the star and planet is r1 than when the
distance between the two bodies is r2.
Suppose instead that K + Ug of the system is B. Which of the following statements are true?
(A) When the separation between the planet and star is r2, the kinetic energy of the system is zero.
(B) The planet and star cannot get farther apart than r2.
(C) This is not a bound system; the planet can escape.
(D) When the separation between the planet and star is r2, the potential energy of the system is zero.