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PRACTICE：Physics Unit33: Astrophysics and Cosmology
本Practice来源于https://webassign.org，是在线Practice的打印版，您也可以访问本平台网站(https://webassign.org/)直接在线完成(注册并登录账号后在首页左侧输入试卷号 332 即可在线作答)，，作答电子化后可随时回放，查看每题答案与详细解析，搜藏保存任意题目；教师使用本平台可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力。本试卷的直接作答链接 https://webassign.org/test332.html
 Author: physics    Total Marks: 24 mks  Marks Awarded: _____________

User Name: No Login  Start Time: 23年05月02日 09:42  Switch to Whole-Paper Mode

Mark Problem
1#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The appearance of the great range of br jv m(myy7evnp6 m64.iightness among stars is due to

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Mark Problem
2#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The absolute luminosity for most stars depends,ie 208lkqdjt on the

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Mark Problem
3#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Four different main-sequenceqyp9 3q wqhp ;dzvz/x)qo 6gq4ys.s4 0 stars are colored blue, orange, red, and yellow. What is their rank fr 94h0p/;. g)yosq 3szqz 4 vyqpx6qwqdom coolest to hottest?

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Mark Problem
4#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  A Hertzsprung-Russell diagram shows stars on a plcr+ w 8-;k9n qtnbmxo1ot of

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Mark Problem
5#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  A white dwarf star with a mass equal to tw ,7s6irb ks*+)4xhjb**dactz c y 1lnhat of the Sun is about the size of

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Mark Problem
6#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Chandrasekhar limit of stellar mass (below which a star will collapse if u6p3w8g x sfrcn7u6/nto a white dwarf) is, if the mass of our Sun8wf r7cux 6fgsp6/u 3n is M, about

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Mark Problem
7#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Supernovas are thoug2 aol-vsz1w2q6ji : ldht to always result in

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Mark Problem
8#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Black holes

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Mark Problem
9#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Pulsars are rapidly spinnrkem; n3 h h;lqa:k6)ning

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Mark Problem
10#
 
Free-Response ( 1.0 marks) Whole-Paper View Save Problem  
State Einstein's principle of equivab7r/e vyggjs c((+)w alence.
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Mark Problem
11#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Schwarzschild radius of a black hole is that radial distance from tw ri 7+ adw(/*:hjm)jmtgsyq0he center of a sphere within(*t agd iw:+mr7j )q/w ymjs0h which not even light can escape. It was first discovered mathematically by Schwarzschild in 1916 after Einstein published his general relativity theory. It can be calculated from a star's mass M as: $R = 2GM/c^2$. Take the radius of both stars A and B as the Schwarzschild radius. If the mass of star A is twice as much as the mass of star B, the average density of star A, compared to star B will be

Correct Answer:    
Mark Problem
12#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  When a distant source emits light of a particular 1 pom:qe24zmjwavelength in the visible, and the source is moving away from us, the color of the light appears to us to be smp zeq12o4j:mhifted toward the

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Mark Problem
13#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The cosmic background radiation corresponds js gog+4io +w3to a temperature of about

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Mark Problem
14#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Sun has apparent brightness at Efht(-8h/n55ef clzsgarth ($1.5 \times 10^{8} \; km$ away) of B. What would be the apparent brightness of the Sun at Pluto, which is $6.0 \times 10^{9} \; km$ from the Sun?

Correct Answer:    
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Mark Problem
15#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  A star has absolute luminosity equal to that of mw 6y-*o qe.fpd+d4i q7i8oduthe Sun ($1.5 \times 10^{8} \; km$ from the Earth) but is 10 pc away from the Earth. By what factor will it appear dimmer than the Sun?

Correct Answer:    
Mark Problem
16#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Earth's orbit has a mean raeq*t /gf3s y1b1 j;gkydius of $1.5 \times 10^{8} \; km$. Over a six-month period, the apparent position of a particular star varies by $0.00014^{\circ}$ due to parallax. How distant is the star, in km?

Correct Answer:    
本Practice全部题目来源于https://webassign.org，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
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Mark Problem
17#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Earth's orbit has a m65qiln-g jw6 aean radius of $1.5 \times 10^{8} \; km$. Over a six-month period, the apparent position of a particular star varies by $0.00014^{\circ}$ due to parallax. How distant is the star, in ly? (1 ly = $9.46 \times 10^{15} \; m$)

Correct Answer:    
Mark Problem
18#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  What is the parallax angle for Proxima Centauri, which,2amz -o jlecqkjf v:++sitdt)0mc0+ is Earth's nearest star at 4.3tjmfqesz2vc, 0 0ml +-+:dk) aoc +tij ly?

Correct Answer:    
Mark Problem
19#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The apparent brightness of a star is:s1p pk)p6jk mqj *+uf $1.0 \times 10^{-12} \; W/m^{2}$ and the peak wavelength is 600 nm. Estimate its distance from us.

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Mark Problem
20#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  It can be shown that the approximate age of the universe is 1/H, where Hg4s:g/+9gz 2(qe o)r, 5kj qfjzyblrx is the Hubble constant. Taking H = 20 km/s/Mly, estimate the age of the universe, in yearzb oqey2g4s/(:,x l qj5f ggrkj9r+z )s.

Correct Answer:    
Mark Problem
21#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  If a galaxy is moving away from us atmx eo.*r*4nnsca+j vmk+j +; t 1.0% of the speed of light, how far away is i++jmk*;nje .nv acmo *xsr 4+tt from us?

Correct Answer:    
Mark Problem
22#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Estimate the speed of a galaxy that is 10 bill;nbz;ne5mt-/u z yn. a/5j, r owvig*oh7*jb zion light-years away.

Correct Answer:    
本Practice全部题目来源于https://webassign.org，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
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Mark Problem
23#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Estimate the observed wavelengzh00daa2jgtoa crm7 i8 b0j x;)-fn :bth for the 656 nm line in the spectrum of a star which is 100 million lia8zt:00fj)xbc 2irjg n b amh0o;-da 7ght-years from us.

Correct Answer:    
Mark Problem
24#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  About 1 ms after the nh0 i(3ehxn2 pBig Bang, the temperature of the universe was about 1013 K. What en eh2h x3n0pn(iergy (in eV) does this correspond to?

Correct Answer:    
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    Total:24 mks Pass:14.4 mks Duration:Unlimited
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