Key, Homework #7, AST 3018, Fall 2011

Key, Homework #7, AST 3018, Fall 2011 - AST 3018 HOMEWORK...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: AST 3018 HOMEWORK #7 DUE 11/29/11 KEY ALL OF THESE PROBLEMS ARE FROM THE TEXT 5.7 You are standing a distance d from a railroad track. Atrain comes past you at a constant speed v, passing you at time t a O. (a) What is the radial velocity of the train as a function of time? (b) Draw a graph of your resultior both positive and negative times. C) At“ x» :meijs-LWEMJLM Wwéifl-rc +- e u Egmmtggmflmmggmgm _________ -mmmywemfiWLgm fmmfiu 0 1.3;: .w MEJLWW WWW. WWW“ WWW” MW WWW “WWW ___m_n__mW mm WWW. mm ,w “mm » _ A)“ :- Ar 53 WWW—.me m”..— mmmmmmmm mmmmWWW.Wm_—. m WMWWWMMM 'f‘ A Q'WWWWWWM WWW WW lllflflflHEI-III-IIIIIIIIIIIIIIIIIIIIII-IIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIlflfiEflIIIIIIIIIIIIII-IIIIII-IIIIIIIIIIII-IEEEIIIIIIIIIIIIII III-IIIIIIIIIIIIEIEJIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIHEIIIIIIIIIIIIIIIII I.III-IIIIIIIIIIIIIFKIIIIII‘ll-IIIIIIIII‘ll-III.-IIEEIIIIIIIIIIIIIIIIII PW ?w 0% IIIIII-IIIIIIIII-IIIIIIIIIIIIIIIIIWII!-III-IIIIIIIII-IIIIIIIIIIIIIIIIII IIIIII-IIIIIIIIIIIIIIIIIIIIIIIIIIIfiII5.III...-IIIIII-IIIIIIIIIIIIIIIIII HI-IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIHIIQIIIIIIIIIIIIII-IIIIIIII‘IIIIIIIII III- IIIIIIIIIIIII III. III. IIIII%II%IIIIIIIII III. III III-III. III- IIIIII-IIIIIIIIIIIIIIIIIIIIIIIII-IQIIEIIII-IIIIIIIII-IIIIIIII-IIIIIIIII ,III-IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIWIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII IIIIII-IIIIIIIIIIIIIIIIIII-IIIIIIIIfiIIIIII-IIIIIIIIIIIIIII-IIIIIIIIIIII IIIIIIIIIIIIII-IIWQIIIIIIIIIIIIIII III-IIIIIIIII III. III-IIIIIIIII IIfifiIIIIIIIIIIIIIIIIIIIII-IIIIIIIIIIII IIIII-I'll...-III@@IIIIIIIIIIIIIIIIIIIIIIIIIII-III..- III.III-IIIII-IIIIIIIIIIIIIIIIIIIIEWIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII III-IIII.IIIIII-IIIIIIIIIIIIIIIIIIIQi-III-IIIIIIIII-IIIIIIIIIIIIIIIIIII IIIII-IIJWIIIII-IiIIIIIIIIIJIIIIIIIIiIIll-IIIIIIIII III-II III- :E kw smfi amL are .5: 1.0 In. 0 9% rs r P? . 12‘ p 4‘ 5.16 Suppose we can measure the positions of stars to 0.01 are sec. How far away could we detect an astrometric binary where the separation is 100 AU? it I)» d fijZ/Czs (ii “:2 r wgégg‘ 6.; «A l AW - C253, if a». a 11;: its at; rte-«W - 3" .‘é‘iji a; .1 s. Nada; mat-(“awe a {0‘99 j 2? a M W alga-A2" jm-*;oi (Question 6.13) If the corona has T = 2 x 106 K, why don’t we see the Sun as a blackbody at this temperature? " “Tl—lg magma}; £5. 5:; Tgfijuems was? Nfi stewséfwfimfi“ @flQEfiTMN ftfisxtLTS Ffi‘fifit fit? a;ng View-en “T if: 5? WT; w P 6.5 How large must the optical depth through a material be for the material to absorb: (a) 1% of the incident photons; (b) 10% of the incident photons; (c) 50% of the incident photons; (d) 99% of the incident photons? East; a”; “r”; Erma/M. sew-i M 9;» =2 "‘7‘" 3: f :1: 0 NMWNW w M a a W 1» Ia Twig e1” moose ‘1?“ Mr“ WC) “Suva .68.) Qi:&ei:: 3;" :oea “team 2'? (fig ‘ so a“ fix” Wrist: Mfifltmf ismfi “em-“Ma em; ‘ to pwflsé’o; as ~- we «no? “i "r ,LwO T “h' “"‘ ”‘ (1)51 PS—wa LL} 6.6 If we have a material that emits uniformly over its volume, what fraction of the photons that we see come from within one optical depth of the surface? . V rw“*fl%'j I E“ 5!“%38. “V1335 jg, 10 M w: M 3% :3 aim «:3 gm if "“ {3’ “‘ 5p J’i‘t, a ,4- 93 e: Hayride: 170 9.2 (a) What is the gravitational potential energy of an interstellar cloud, with a density of 1000 H atoms/cm3 and a radius of 10 Pc? (b) What is its kinetic energy if its temperature is 10K? aw; @flfia fay; wGV : Q figwfiz [ism/ways 5" W ’ ‘3 2, (4‘3: 5m ‘“ WHEEfifE m :: .iflcggfiék‘fin? 5-; Maya/CM“: 2 IN» ' I m -2“ "2i . i at; .. i we as; €33 “99/ch 4,4312% 'gfiw " “é? 55f @200 Poi: Maggi”? M x 3 Mfg? '2” L 0" M t It!) *5? 5 s y dyad M ;) iii—23 7g“; 3:: Q T? Uta w wk MP: 1 - w g“ $ w 63:} $39573 Kn} 4 fifibfliffififlfi'Wfi ’Aii - n wtfififlfi iii/r" MV’ “nee K N Kg“: T Tde 3l5>§l0 “g: 2» W5 ~ i oiw W? L4 3 w u, 3 A MiG-0?! W e! 5 WE“ fly 2;“ 'ffbwfiffifi fl“; «— E r CW3 £3 In 9.4 Estimate the lifetime of a 10 Ms star on the main sequence to give off energy stored from gravitational collapse? Fé 9% PrPfeav’Qix r5: Ex?§fi£cbhfié mere: film-e Luwzfifljs?‘§f Fug A 5 in M ‘srfifik 3"" 'u: f: 3 gig,‘ in» .3 3: A E $ , hem “ fig {3" ) Lime ‘ “if m j ‘glfinfi “3 M4 s5 29‘ fl mfg-y- “Unrzxwl’ gag: Q33 i fl 7. 5 A 3. 2” biwbg’ EQwefiefi :5 as?“ a "3 C?“ MWM/{éifime . 2‘ H0 mg l3 e i enfiVE " §3Ek1f%fl§)§fi tifwfliigtfiw “’5 f 3" ‘5 <5 {36 m5 flew-fi- my? "f. £5 6: Vatatej: t-” ,MMEE 7‘? As...— nil is??? m : flfii» «29% w §_ a; 6% "ES ‘3 gem/L “This arm :3”; gfiE gg‘wfifieflws 5 m 5;: “I L {incl 2. W" 3 :taaffi‘? t5 m {PI/Li 'tsTfiffi 7:. €535: “'5' ‘3’ a; 3.87%” Egg, Lfamflw 3375 a? a, sgagiaf" :3 ck {Sfiga‘f a 5 US: in 9.8 Calculate the binding energy of a 4He nucleus. :3 / £9 ? 339%! go “3% 5E :2 WM awmw «2: mag: W1 :5; f, 7"? t? 4?; £53 {kW—v m a, .“m'l M951“ '(«té‘flf Xi; film .242} {8X 59% 2., . 'F I . I M Bfi:@3%1tfifimemAwa9Mu ?”x. @c in er 1 up __ MT 4 W BE : jogximwpfixim M‘é wfi'dfizo e6; 9 LijWQgflgjfi :2 2‘ (afgwgiflvr e was Met! Mmm g, a, t»: {e e‘Q/w BE: 14.2 We observe a star that is 1000 pc away. How much extinction. would there be if we calculated a distance of 2000 pc when we didn’t take extinction into account? x a M x R .ft sflN‘fifigg-UJ R; 2.5399 {Dame i ” ‘Mm - ‘ ‘ “WW resin mt? w 5 .rxmfiwx {woof ow, \. - Q -= FT H C watermavzfii” “ In, :3: 39m} P M f m Mrw—{M :1: fififmficfrmfl ft mffi’i‘ 33ft.» 5‘ n 5” foe; it; M 5’; fix n) W m {m w i gm Jew :5“ lg? lg fwwmsiogfiwfwg DID 5M (0 '"\Z> 3? W “A {9 M ‘ ~ - 55”} 093 :1 L3 (gmwcfiwj mimmflfl :E‘iwée “W 14.5 We are observing a cluster whose distance is known to be 850 pc. The visual extinction between us and the cluster is 2 magnitudes. What would be the m, and mg for (a) an 05 star and (b) a GE star? an I l M *1 {A3232 fifPENQm E "(’9 @315?” My. {3mg swig rm; we; we“ r, "a I.“ :1 9 r” 61-3 £35" melt M¢w~élulm§ MAJ ,m firefly "* filv «gm é.” gd§fi~w AV wfifiRF R M E; V r “' 2, Esta; Wt 31 ~éloefiw§lfi> rel “'“éfi‘iflt‘g “'5” Ar (.3 {Q Wgfimtvwwm : silag- '"’*“ .. 17., 53",“? bjGS' ates“? ffign‘té We {will ...
View Full Document

Page1 / 7

Key, Homework #7, AST 3018, Fall 2011 - AST 3018 HOMEWORK...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online