INQUIRY INTO PHYSICS-EBOOK
8th Edition
ISBN: 9780357540039
Author: Ostdiek
Publisher: CENGAGE L
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 12, Problem 18P
To determine
The ratio of
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Problem 2: Black hole – the ultimate blackbody
A black hole emits blackbody radiation called Hawking radiation. A black hole with mass
M has a total energy of Mc², a surface area of 167G²M² /c*, and a temperature of
hc³/167²KGM.
a) Estimate the typical wavelength of the Hawking radiation emitted by a 1 solar
mass black hole (2 × 103ºkg). Compare your answer to the size of the black hole.
b) Calculate the total power radiated by a one-solar mass black hole.
c) Imagine a black hole in empty space, where it emits radiation but absorbs nothing.
As it loses energy, its mass must decrease; one could say "evaporates". Derive a
differential equation for the mass as a function of time, and solve to obtain an
expression for the lifetime of a black hole in terms of its mass.
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…
What is the escape velocity Vesc of a 1.4M⊙ 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.]
Chapter 12 Solutions
INQUIRY INTO PHYSICS-EBOOK
Ch. 12 - Prob. 1AACh. 12 - Prob. 2AACh. 12 - Prob. 1PIPCh. 12 - Prob. 1MIOCh. 12 - Prob. 2MIOCh. 12 - Prob. 1QCh. 12 - Prob. 2QCh. 12 - Prob. 3QCh. 12 - Prob. 4QCh. 12 - Prob. 5Q
Ch. 12 - Prob. 6QCh. 12 - Prob. 7QCh. 12 - Prob. 8QCh. 12 - Prob. 9QCh. 12 - (Indicates a review question, which means it...Ch. 12 - Prob. 11QCh. 12 - Prob. 12QCh. 12 - (Indicates a review question, which means it...Ch. 12 - Prob. 14QCh. 12 - Prob. 15QCh. 12 - Prob. 16QCh. 12 - Prob. 17QCh. 12 - Prob. 18QCh. 12 - Prob. 19QCh. 12 - Prob. 20QCh. 12 - Prob. 21QCh. 12 - Prob. 22QCh. 12 - Prob. 23QCh. 12 - Prob. 24QCh. 12 - Prob. 25QCh. 12 - Prob. 26QCh. 12 - Prob. 27QCh. 12 - Prob. 28QCh. 12 - Prob. 29QCh. 12 - Prob. 30QCh. 12 - Prob. 31QCh. 12 - Prob. 32QCh. 12 - Prob. 33QCh. 12 - Prob. 34QCh. 12 - Prob. 35QCh. 12 - Prob. 36QCh. 12 - Prob. 37QCh. 12 - Prob. 38QCh. 12 - Prob. 39QCh. 12 - Prob. 40QCh. 12 - Prob. 41QCh. 12 - Prob. 42QCh. 12 - Prob. 43QCh. 12 - Prob. 44QCh. 12 - Prob. 1PCh. 12 - How fast would a muon have to be traveling...Ch. 12 - The lifetime of a free neutron is 886 s. If a...Ch. 12 - Prob. 4PCh. 12 - The formula for length contraction gives the...Ch. 12 - Prob. 6PCh. 12 - Prob. 7PCh. 12 - Prob. 8PCh. 12 - Prob. 9PCh. 12 - . In a particular beam of protons, each particle...Ch. 12 - . A particle of rest energy 140 MeV moves at a...Ch. 12 - . If the relativistic kinetic energy of a particle...Ch. 12 - Prob. 13PCh. 12 - Prob. 14PCh. 12 - Prob. 15PCh. 12 - . How many years would you have to wait to observe...Ch. 12 - Prob. 17PCh. 12 - Prob. 18PCh. 12 - . A compact neutron star has a mass of kg (about...Ch. 12 - Prob. 20PCh. 12 - Prob. 21PCh. 12 - Prob. 22PCh. 12 - Prob. 23PCh. 12 - Prob. 24PCh. 12 - Prob. 25PCh. 12 - Prob. 26PCh. 12 - Prob. 27PCh. 12 - Prob. 28PCh. 12 - Prob. 29PCh. 12 - Prob. 30PCh. 12 - Prob. 31PCh. 12 - . If the average lifetime of a proton was 1033...Ch. 12 - Prob. 1CCh. 12 - Prob. 2CCh. 12 - Prob. 3CCh. 12 - Prob. 4CCh. 12 - Prob. 5CCh. 12 - Prob. 6CCh. 12 - Prob. 7CCh. 12 - Prob. 8CCh. 12 - Prob. 9CCh. 12 - Prob. 10C
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
- 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.arrow_forwardwhat 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_forward(a) Estimate the Eddington luminosity of a 0.072 M, star and compare your answer to the main-sequence luminosity given in Problem 21. Assume k = 0.001 m² kg¯'. Is radia- tion pressure likely to be significant in the stability of a low-mass main-sequence star? (b) If a 120 Mo star forms with log1o T. = 4.727 and log1o(L/Lo) = 6.252, estimate its Eddington luminosity. Compare your answer with the actual luminosity of the star.arrow_forward
-  Q/ b) Vega Star of radius (1.6832) million km emit a) thermal radiation as a black body radiation at temperature of (18500 K). Calculate the Luminosity of this star. [o is Stefan-Boltzmann constant = 5.67 *x 10-5 erg cm-2 K-4 s-1]arrow_forwardwhat is the answer for sub-item (b) if the radius of the neutron star is 84.66 km?arrow_forwardAs a mass m of gas falls into a black hole, at most 0.1mc2 is likely to emerge as radiation; the rest is swallowed by the black hole. Show the Eddington luminosity for a black hole of mass M is equivalent to 2*10-9 Mc2yr-1. Explain why we expect the black hole's mass to grow by at least a factor of e every 5*107 years. Where Edding Luminicity is defined as LE=(4piGMmpc)/(sigmaT), where G is the gravitational constant, M is the mass of the black hole, mp is the mass of a proton, c is the speed of light, and sigmaT is Thomson scattering where sigmaT=6.653*10-25 cm2.arrow_forward
- what 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_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_forwardA star has initially a radius of 680000000 m and a period of rotation about its axis of 26 days. Eventually it changes into a neutron star with a radius of only 40000 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. 3.25E+15 Ob. 25.7 Oc. 0.0389 Od. 3.08E-16 (b) the ratio of initial to final kinetic energy Oa. 2.74E-23 Ob. 437000 Cc. 2.29E-6 FUJITSUarrow_forward
- A star has initially a radius of 640000000 m and a period of rotation about its axis of 20 days. Eventually it changes into a neutron star with a radius of only 50000 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. 1.42E+15 Ob. 19 Oc. 0.0527 Od. 7.06E-16 (b) the ratio of initial to final kinetic energy Oa. 8.18E-23 Ob. 456000 Oc. 2.19E-6 Od. 1.22E+22 52%arrow_forwardA star has initially a radius of 780000000 m and a period of rotation about its axis of 22 days. Eventually it changes into a neutron star with a radius of only 25000 m and a period of 0.1 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) a. 1.85E+16 b. 51.2 c. 0.0195 d. 5.4E-17 (b) the ratio of initial to final kinetic energy a. 2.84E-24 b. 371000 c. 2.69E-6 d. 3.52E+23arrow_forwardA nova dwarf has: mass 0.85 Mʘ, radius 0.0095 Mʘ, transfer rate ofmass 5.0 × 10-10 Mʘ / year during its active phase lasting 10 days. Estimate the total energy released and the absolute brightness of dwarf nova during the active phase.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStax
Modern PhysicsPhysicsISBN:9781111794378Author:Raymond A. Serway, Clement J. Moses, Curt A. MoyerPublisher:Cengage Learning
Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Astronomy
Physics
ISBN:9781938168284
Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher:OpenStax
Modern Physics
Physics
ISBN:9781111794378
Author:Raymond A. Serway, Clement J. Moses, Curt A. Moyer
Publisher:Cengage Learning
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning