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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 gr v/ee8kcnc )/x4l 9akreat range of brightness 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 stn:fzp03 be5 xnars depends on the

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Mark Problem
3#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Four different main-sequence stars are colored blu,siit ddv ube;+u88-q e, orange, red, and yellow. Whatiqevt +,uu8d-b is8;d is their rank from 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 sta5gj , j0lxkxa;rs on a plot 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 tg+ vda, (qo*/rqynr1do that 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 limi1i/fnr( nj 8;wlrp: xyt of stellar mass (below which a star will collapse into a white dwarf) is, if the mass ofjnpn1x/fwr( ;r:l8yi our Sun is M, about

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Mark Problem
7#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Supernovas are thought to always result inz2m +41juvl+x2asx fh

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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 spinnia7ia,xf .,q/ -21bhfxlxvo jsng

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Mark Problem
10#
 
Free-Response ( 1.0 marks) Whole-Paper View Save Problem  
State Einstein's principle of g)dfy,ch(u y ,k2h me+equivalence.
Correct Answer:    
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Mark Problem
11#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Schwarzschild radius omarh:y6x 5 r2uf a black hole is that radial distance from the center of a sphere within 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 masur 2mhxay6r5: s 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

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Mark Problem
12#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  When a distant source emits light of aa/ ft9hld o,7h um 5ehkb.v.9 j9yc:nt-rldl4 particular wavelength in the visible, and the source is moving away from us, the color of the light appears to us tvkl/h j.bhrylt 9 d h,f9.cutl:a7d45- 9 emono be shifted toward the

Correct Answer:    
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教师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
Mark Problem
13#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The cosmic backgrounwsa5rz9p:2 6ctkpnf( d radiation corresponds to 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 Ealihax 75-8wu(m vo7ban-4pyop 0o2 jdrth ($1.5 \times 10^{8} \; km$ 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?

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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 the Sun (cj9ztzjnlns +hug 2;nqj 9u;a)sith) -if63 1$1.5 \times 10^{8} \; km$ from the Earth) but is 10 pc away from the Earth. By what factor will it appear dimmer than the Sun?

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Mark Problem
16#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Earth's orbit has a mean radiust ez;p kg5;x1t 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?

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Mark Problem
17#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Earth's orbit has a mp bwkz;rv:emqn;,(m d:8 da0rxklz66ean 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, wh/*s6d gn3 famtich is Earth's nearest star at 4.3 ldatn *36/gfmsy?

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Mark Problem
19#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The apparent brightnesko 9vct:no0 dau m(p;+s of a star is $1.0 \times 10^{-12} \; W/m^{2}$ 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, whereqvz+xxx p *p;x0+r ah. H is the Hahv xz ;+*x0rpxp.qx +ubble constant. Taking H = 20 km/s/Mly, estimate the age of the universe, in years.

Correct Answer:    
Mark Problem
21#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  If a galaxy is moving away from us at 1.0% of the speed of lightsl,bryd7l /mkx f)-ju2, 5y1 3axn2yeo 6ck xy, how far away is it from us?dj 62oy k,b xa5rl2-u3fyyse)m, kcxly/nx71

Correct Answer:    
Mark Problem
22#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Estimate the speed of a galaxy that is 10 billion light-yj +bu4w y -/hqz(vi0c7y0vqvxears away.

Correct Answer:    
Mark Problem
23#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Estimate the observed waveleng+s e ej-xg/u1pth for the 656 nm line in the spectrum of a star whichsje-g1 ex+p /u is 100 million light-years from us.

Correct Answer:    
Mark Problem
24#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  About 1 ms after the Big Bang, the temperature of the 3k;esroiqw.j4z y( g x2j(,eg(oh .iq universe was about 1013 K. What enerzqjqh(k(3( oey24jrgioiw, ;gxs. e. gy (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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