Chapter 13 problem 58 of fundamentals of physics extended(8th) \"The presence of

Question

Chapter 13 problem 58 of fundamentals of physics extended(8th) "The presence of an unseen planet orbiting a distant star cansometimes be inferred from the motion of the star as we see it. Asthe star and planet orbit the center of mass of the star-planetsystem, the star moves toward and away from us with what is calledthe line of sight velocity, a motion that can be detected. figure13-50 shows a graphy of the line of sight velocity versus times forthe star 14 herculis. This graph shows the star moves at 70 m/s andhas a period of 1500 days. The star's mass is believed to be .9 ofthe mass of our sun. assume that only one planet orbits the starand that our view is along the plane of the orbit. Then approximate(a) the planet's mass in terms of Jupiter's mass and (b) theplanet's orbital radius in terms of Earth's orbital radius." I am having trouble understanding this entire problem. I was under the impression that the velocity measured was thatof the star in this star-planet system. if that is so how is itthat we are setting that velocity equal to the 2piR/T for theplanet. because if the planet and the star both have the sameperiod yet differing distances from the center of mass wouldn'tthat make the planet's velocity far greater? and I am especiallyconfused about the 2nd to last step in part B of the problem. itsays that (70 X 1500 X 8.64 X 10^4) / 2pi = 5.274 X 10^11. mycalculator tells me it is instead = 1.444 X 10^9. Chapter 13 problem 58 of fundamentals of physics extended(8th) "The presence of an unseen planet orbiting a distant star cansometimes be inferred from the motion of the star as we see it. Asthe star and planet orbit the center of mass of the star-planetsystem, the star moves toward and away from us with what is calledthe line of sight velocity, a motion that can be detected. figure13-50 shows a graphy of the line of sight velocity versus times forthe star 14 herculis. This graph shows the star moves at 70 m/s andhas a period of 1500 days. The star's mass is believed to be .9 ofthe mass of our sun. assume that only one planet orbits the starand that our view is along the plane of the orbit. Then approximate(a) the planet's mass in terms of Jupiter's mass and (b) theplanet's orbital radius in terms of Earth's orbital radius." I am having trouble understanding this entire problem. I was under the impression that the velocity measured was thatof the star in this star-planet system. if that is so how is itthat we are setting that velocity equal to the 2piR/T for theplanet. because if the planet and the star both have the sameperiod yet differing distances from the center of mass wouldn'tthat make the planet's velocity far greater? and I am especiallyconfused about the 2nd to last step in part B of the problem. itsays that (70 X 1500 X 8.64 X 10^4) / 2pi = 5.274 X 10^11. mycalculator tells me it is instead = 1.444 X 10^9.

Explanation / Answer

Given : As we know that v = GM/R and T = 2 R/g From the above two equations we can write   v = 2 Rp / T      Rp = v * T / 2            =   (70 X 1500 X 8.64 X 104) / 2            = 907200 * 104 / 2            =144385.36 * 104            =1.44385 * 109 I hope it helps you I hope it helps you

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.