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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 brightness gdf1 (mb3(qcm 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 ovzn58lex e3;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 blue, orange,5bsa37itzzw) red, and yellow. What is thea 5wi7)zs bzt3ir 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 stars on a plo0 nerq 7cey n1b6yp5q5t 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 k wfg2.u8ul9xui ye(4ye j8.eto 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 limit of stellar mass (below which a k 8gjj:2qq/q e ye.l-mstar will collapse into a white dwarf) is, if th2g : l/mjqeqk-ejq .y8e mass of 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 tonuxtww**aszx 3( ni 4, 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 ;j zl*kbba g4 v+zx4+ 8oh2;iizd(rhuspinning

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Mark Problem
10#
 
Free-Response ( 1.0 marks) Whole-Paper View Save Problem  
State Einstein's principle of equivalenceb vwhrdt+r, d4mwax2 29oenxk1e 5u53 .
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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 the ce8g 5-g 1nt pgtvy*w+u;ie rw1onter of a sphere within which not even light can escape. It was first discovered mathematically by Schwarzschild in 191618e-5* twygguontvr ;1 i gpw+ 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

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Mark Problem
12#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  When a distant source emits light of a particul ab6 4ks1ft;h bi.)x5jys-w jpar wavelength in the visible, and the so ;ba ywjs t)-hkxfp1j bi.456surce is moving away from us, the color of the light appears to us to be shifted toward the

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Mark Problem
13#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The cosmic background radiatilues/4z.d 9l0jjzoo-on 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 Emc f2h,c rxc7p th:5-uarth ($1.5 \times 10^{8} \; km$ 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 thehlupol00 82c g 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?

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Mark Problem
16#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Earth's orbit has a mea9f6(,cdnb,jwg e *l b39jyv can 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 km?

Correct Answer:    
Mark Problem
17#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Earth's orbit has a mean radius of ynk7utj6b t1d896ky7 hcv5 l c$1.5 \times 10^{8} \; km$. 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, whl5x s q xzi4)*tgg-g77+t qmykich is Earth's nearest star at glt*x+4ks7xt qz7 my)g-5g iq 4.3 ly?

Correct Answer:    
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Mark Problem
19#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The apparent brightness of a starm ri,x2x)jtut k (5ehv97k uj;rxv(p0 is $1.0 \times 10^{-12} \; W/m^{2}$ and the peak wavelength is 600 nm. Estimate its distance from us.

Correct Answer:    
Mark Problem
20#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  It can be shown that 2-cz)4m84fh sp kytbvthe approximate age of the universe is 1/H, where H is the Hubble constant. Taking H = 20 k )2 ckh4sp8-tvfym4bz m/s/Mly, estimate the age of the universe, in years.

Correct Answer:    
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Mark Problem
21#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  If a galaxy is moving away from us a-vh5i xw ,iszzo: ()jq13ux*s )uofkvt 1.0% of the speed of light, how far away is it from u1v,i*f-xjuo()5)sqok z zwuivh3x:s s?

Correct Answer:    
Mark Problem
22#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Estimate the speed of a galaxy that is 10 bi)gtux9 z6 je+6v)plnw)gvnw/c -0x cellion light-years away.

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Mark Problem
23#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Estimate the observed wavelength for the 656 nm 2ygnu4tgt0uz (3 okk/ line in the spectrum of a star which ist 4(ou3tk2ky0ugnz /g 100 million light-years from us.

Correct Answer:    
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Mark Problem
24#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  About 1 ms after the Big Bang, the tem54xg fp ;fn .;cynu imd,k.sn3ew*w 7cperature of the universe was about 1013 K. What energy (in cdfx.su4;5w n ,7nf3*nmcypig ewk.;eV) does this correspond to?

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