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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 among stars ix 0v.wctt(xh 0o(oak5m7qh m 0s due to

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Mark Problem
2#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The absolute luminosity for my4 vm+svqvq x+x/ ;.cf6ozghxc .c+n )ost stars depends on the

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Mark Problem
3#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Four different main-sequence st lmm32+kx)y lyars are colored blue, orange, red, and yellow. What is their rank from coolest to hottesxm ykl2)+ly m3t?

Correct Answer:    
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Mark Problem
4#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  A Hertzsprung-Russell diagram shows otjsmh6 t 3g8.stars 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 to that of the Sun is about theha90rnp-plc shjc ) 5pby; ldo3 e7;p- size of

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
6#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Chandrasekhar limit of stellar mass (below which :9cpn 9da+i3jhcv y7sa star will collapse into a white dwarf) is, if the mass of our Sun is M,ydjvp:h c97+3cnisa 9 about

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Mark Problem
7#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Supernovas are thought to always result inktd cn9 )a(3xgmqa5u6gglv* 7

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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 spin4 6jtu7lgz 4ntning

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Mark Problem
10#
 
Free-Response ( 1.0 marks) Whole-Paper View Save Problem  
State Einstein's principle of equivalench;h rf8gt 1:sce.
Correct Answer:    

Mark Problem
11#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Schwarzschild radius of a black hole is that radial distance 88t: b jme4tz-oa) 9dyvgc*f afrom 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 relat4jt8-om:8)zvaa d*9 bt fgeycivity 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 wavelength in the vx(we1t2b-y mm32i;rc e g6rv visible, and the source is moving away from us, the color of the light appears to us to be shifti6 x;rv-b ytev w2e3rm mg21c(ed toward the

Correct Answer:    
Mark Problem
13#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The cosmic background radiation corresponds to a)ee1h ro,cim-ma.nw87 f y 6mk temperature of about

Correct Answer:    
Mark Problem
14#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Sun has apparent:dah;xy0apftmgi.3md /e )y 1 brightness at Earth ($1.5 \times 10^{8} \; km$ 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:    
Mark Problem
15#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  A star has absolute luminosity equal to1a* vh.oa 8knv that of the 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 radius ohhe80o xm2pc ,d)0pfo f $1.5 \times 10^{8} \; km$. 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:    
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Mark Problem
17#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The Earth's orbit has a mean radius of ;g vzed4y/ cv1 lt8 zkhcc7u/4$1.5 \times 10^{8} \; km$. 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 is Earth's xtfx+q,s xmal7ho. 16nearest star at xmt 7l1fx ,6h s+qxo.a4.3 ly?

Correct Answer:    
Mark Problem
19#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  The apparent brightnessvsy m9(//lh / g)pxjdt of a star 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 the approximate age of thetqt ar,-x(:6u nt:h+dc b d)gp universe is 1/H, where H is the :x 6ttddbt:p,- a+g hu(r)nqcHubble constant. Taking H = 20 km/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 m0qj r/ -ztd2)nj2phrat 1.0% of the speed of light, how far away is it fmz t2prrn2jjq-h0)d/rom 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 billion light-yearaylmf b z+a3wv:4 gv.yqj3 6b:s away.

Correct Answer:    
Mark Problem
23#
 
Single-Choice ( 1.0 marks) Whole-Paper View Save Problem  
  Estimate the observed,fh 7b+sy st++ o)puhr wavelength for the 656 nm line in the spectrum of a star which is 100 million l+ +phtr,o7+b) fshsuyight-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 faz/ l1gp1cv/of the universe was about 1013 K. What energy (in eV) does this corpza 1/f /cglv1respond to?

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