A comet is in an elliptical orbit around the Sun, thanks to the Sun’s gravitational pull; this force is always towards the Sun. In the diagram below the comet is moving clockwise, and the position at five different times is shown. A.) Draw the force and the velocity vectors of the comet onto the diagram at each of the five positions A-E. B.) At each of the positions, is the work done by the gravitational force of the Sun positive, negative or zero? Underline the correct answer, and briefly explain: A: W > 0 W < 0 W = 0 B: W > 0 W < 0 W = 0 C: W > 0 W < 0 W = 0 D: W > 0 W < 0 W = 0 E: W > 0 W < 0 W = 0 At which position is the kinetic energy of the comet greatest? Why C.) What is (i.e., calculate) the torque of the force of gravity relative to the Sun’s position? Com- ment on/calculate the vector angular momentum of the comet relative to the Sun’s position, and discuss the variation of the speed of the comet along its orbit.

A comet is in an elliptical orbit around the Sun, thanks to the Sun’s gravitational pull; this force is always towards the Sun. In the diagram below the comet is moving clockwise, and the position at five different times is shown. A.) Draw the force and the velocity vectors of the comet onto the diagram at each of the five positions A-E. B.) At each of the positions, is the work done by the gravitational force of the Sun positive, negative or zero? Underline the correct answer, and briefly explain: A: W > 0 W < 0 W = 0 B: W > 0 W < 0 W = 0 C: W > 0 W < 0 W = 0 D: W > 0 W < 0 W = 0 E: W > 0 W < 0 W = 0 At which position is the kinetic energy of the comet greatest? Why C.) What is (i.e., calculate) the torque of the force of gravity relative to the Sun’s position? Com- ment on/calculate the vector angular momentum of the comet relative to the Sun’s position, and discuss the variation of the speed of the comet along its orbit.