Foundations of Astronomy (MindTap Course List)
14th Edition
ISBN: 9781337399920
Author: Michael A. Seeds, Dana Backman
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 14, Problem 16RQ
To determine
The velocity (in terms of
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
What is the escape velocity Vesc of a 1.4?⊙
neutron star if its radius is 12 km? Express your answer as a multiple of the speed of light (i.e., compute Vesc/c, where c= 2.9979 x 105 km/s).
[Hint: you will need to recall the formula for escape speed from the surface of an object. This was discussed when we covered planetary atmospheres.]
A star with mass m, period Ti = 30 days, and radius ri = 1E4 km collapses into a neutron star (Links to an external site.) with a radius of rf = 3 km. Our goal will be to determine the period Tf of the neutron star. Useful formulae: Li=Lf; L=Iω; ω=2πf=2π/T; Isphere=2/5mr^2.
1.How much angular momentum Li does the star have before it collapses?
2. What is the rotation rate ωi of the star before collapsing?
3. Suppose we model the star as a solid sphere of radius ri with moment of inertia 2/5mri2 (a good assumption). What does our description of Li read now?
4.How much angular momentum Lf does the star have after it collapses?
5. What is the rotation rate ωf of the star after collapsing?
6.The new object, a neutron star, is also shaped like a sphere. What does Lf read?
Group of answer choices
7.Assuming angular momentum is conserved during collapse (also a good assumption), what is our prediction for the period of the neutron star, Tf?
8. What is Tf in units of days?
9. What…
A star with mass m, period Ti = 30 days, and radius ri = 1E4 km collapses into a neutron star (Links to an external site.) with a radius of rf = 3 km. Our goal will be to determine the period Tf of the neutron star. Useful formulae: Li=Lf; L=Iω; ω=2πf=2π/T; Isphere=2/5mr^2.
Chapter 14 Solutions
Foundations of Astronomy (MindTap Course List)
Ch. 14 - Prob. 1RQCh. 14 - Prob. 2RQCh. 14 - Prob. 3RQCh. 14 - Prob. 4RQCh. 14 - Prob. 5RQCh. 14 - Prob. 6RQCh. 14 - Prob. 7RQCh. 14 - Prob. 8RQCh. 14 - Prob. 9RQCh. 14 - Prob. 10RQ
Ch. 14 - Prob. 11RQCh. 14 - Prob. 12RQCh. 14 - Prob. 13RQCh. 14 - Prob. 14RQCh. 14 - Prob. 15RQCh. 14 - Prob. 16RQCh. 14 - If the Sun has a Schwarzschild radius, why isnt it...Ch. 14 - Prob. 18RQCh. 14 - Prob. 19RQCh. 14 - Prob. 20RQCh. 14 - Prob. 21RQCh. 14 - In what sense is a black hole actually black?Ch. 14 - If you are falling into a black hole and you point...Ch. 14 - Prob. 24RQCh. 14 - Prob. 25RQCh. 14 - Prob. 26RQCh. 14 - How Do We Know? How does peer review make fraud...Ch. 14 - Prob. 1PCh. 14 - Prob. 2PCh. 14 - Prob. 3PCh. 14 - Prob. 4PCh. 14 - Prob. 5PCh. 14 - Prob. 6PCh. 14 - Prob. 7PCh. 14 - Prob. 8PCh. 14 - Prob. 9PCh. 14 - Prob. 10PCh. 14 - Prob. 11PCh. 14 - Prob. 12PCh. 14 - Prob. 13PCh. 14 - Prob. 14PCh. 14 - Prob. 15PCh. 14 - Prob. 16PCh. 14 - Prob. 1SOPCh. 14 - Prob. 2SOPCh. 14 - Prob. 1LTLCh. 14 - Prob. 2LTLCh. 14 - Prob. 3LTLCh. 14 - Prob. 4LTLCh. 14 - Prob. 5LTL
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- what is the answer for sub item (b) if the radius of the neutron star is 69.601 km? (express your answer in the proper SI unit ans without scientific notation)arrow_forwardWhat is the orbital period (in s) of a bit of matter in an accretion disk that is located 6 ✕ 105 km from a 99 M black hole? Hint: Use the circular orbit velocity formula, Vc = GM r . sarrow_forwardTime left 1:45:56 A star has initially a radius of 680000000 m and a period of rotation about its axis of 33 days. Eventually it changes into a neutron star with a radius of only 45000 m and a period of 0.3 s. Assuming that the mass has not changed, find Assume a star has the shape of a sphere. (Suggestion: do it with formula first, then put the numbers in) [Recommended time : 5-8 minutes] (a) the ratio of initial to final angular momentum (Li/Lf) Oa. 2.17E+15 Ob. 24 Oc. 0.0416 Od. 4.61E-16 (b) the ratio of initial to final kinetic energy Oa. 4.85E-23 Ob. 396000 Oc. 2.53E-6 Od. 2.06E+22arrow_forward
- what is the answer for sub-item (b) if the radius of the neutron star is 68.283 km? (express your answer in the proper SI unit and without scientific notation)arrow_forwardwhat is the answer for sub-item (b) if the radius of the neutron star is 6.676 km? (express your answer in the proper SI unit and without scientific notation) (b)What is the average density of a neuron star that has the same mass as the sun but a radius of only 20.0 km?arrow_forwardWhat is the Schwarzschild radius of a star with a mass of z × 10 Mun? The answer is in 106m. So if you calculated an answer like 157,895,250 convert it like this: 106 157, 895, 250 × 157.9 and that is what you will input 100000 z =2.57 y =3 M Sun = 2 × 10³⁰ kg =arrow_forward
- The velocity curve for a double spectroscopic binary is shown in the sketch. The system is viewed edge-on, i.e., with an inclination angle of i = 90°, so that the maximum possible Doppler shifts for this system are observed. line 400 So = U, Ani 300 200 loo = v Ain i 100 -100 -200 -300 400 • 1 2 3 • s 7 a 10 Time (days) Find the mass of star 1, mı, in terms of solar masses. 1 solar mass = 2x1030kg Round your answer to three significant figures. Doppler Velocity (20su)arrow_forwardThe star HD 69830's mass is 1.7 ✕ 1030 kg, its radius is 6.3 ✕ 105 km, and it has a rotational period of approximately 35 days. If HD 69830 should collapse into a white dwarf of radius 7.8 ✕ 103 km, what would its period (in s) be if no mass were ejected and a sphere of uniform density can model HD 69830 both before and after?arrow_forwardA star has initially a radius of 660000000 m and a period of rotation about its axis of 34 days. Eventually it changes into a neutron star with a radius of only 35000 m and a period of 0.2 s. Assuming that the mass has not changed, find Assume a star has the shape of a sphere. (Suggestion: do it with formula first, then put the numbers in) [Recommended time : 5-8 minutes] (a) the ratio of initial to final angular momentum (Li/Lf) Oa. 5.22E+15 Ob. 24.2 Oc. 0.0413 Od. 1.91E-16 (b) the ratio of initial to final kinetic energy Oa. 1.3E-23 Activate V Go to Setting Ob. 607000 Oc. 1.65E-6 e here to searcharrow_forward
- International Astronomical Union reported on 24 Feb 1987: An object was discovered on Feb. 24.37 UT (position R.A. = 5h35m.8, Decl. = -69 18'), obtained m = 4.8 on Feb. 24.454 UT. This object proved to be the most famous supernova (SN) in the 20th Century and the brightest visible from Earth since 1604. It is classified as a SN of the type Il in the Large Magellanic Cloud (SN1987A). Its brightness peaked in May 1987, with an apparent magnitude of m = 2.8. a) Find the absolute magnitude M of the SN1987A at maximum. Distance of the LMC is 51,400 pc. b) The progenitor (before SN explosion) star was a blue supergiant of the apparent magnitude m = 12.8. How much brighter (in terms of flux density) this SN was at maximum compared to the progenitor star. Find the ratio FSN / Ebeforearrow_forwardWhat must be the radius of a star of mass 2 x 10^30 kg so that the escape speed from this star is equal to 2 × 10^8 m/s?arrow_forwardwhat is the answer for sub-item (b) if the radius of the neutron star is 84.66 km?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning