Astro 210 Exam 2 Front Page - kg R = 7 . 10 8 m R Earth = 6...

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Astronomy 210 Spring 2011 HOUR EXAM 2 1. DO NOT OPEN THIS EXAM UNTIL INSTRUCTED TO DO SO. 2. Write you name and all answers in your test booklet. Turn in everything: your booklet, and the questions. 3. Show all of your work in the test booklet, and indicate clearly your Fnal answer! A correct Fnal answer may not receive credit if no work is shown. 4. Budget your time! Don’t get stalled on any one question. 5. ±or your reference there are formulas below. Many of these constants and formulas you will not need for this exam! Possibly Useful Formulae Astronomical Unit: 1AU = 1 . 5 × 10 11 m. gravitational constant : G = 6 . 7 × 10 11 m 3 kg 1 s 2 speed of light: c = 3 . 0 × 10 8 m s 1 Stefan-Boltzmann constant: σ = 5 . 7 × 10 8 W m 2 K 4 Planck’s constant: h = 6 . 6 × 10 34 J s = 4 . 1 × 10 15 eV s electron Volt: 1 eV = 1 . 6 × 10 19 J Boltzmann constant: k = 1 . 4 × 10 23 J K 1 mass of the proton: m p = 1 . 7 × 10 27 kg M = 2 . 0 × 10 30 kg M Earth = 6 . 0 × 10 24 kg M Jupiter = 1 . 9 × 10 27
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Unformatted text preview: kg R = 7 . 10 8 m R Earth = 6 . 4 10 6 m R Jupiter = 7 . 10 7 m L = 3 . 8 10 26 Watt T = 5800 K age of Sun 4 . 6 10 9 yr v F = mva v L = mv r v p V circ = 2 r/P = r a c = V 2 /r v F = Gm 1 m 2 /r 2 r PE = Gm 1 m 2 /r V 2 circ = GM/r a 3 AU = P 2 yr a 3 = GMP 2 / 4 2 f = c E = hf = hc/ dif = 1 . 22 /D max T = 2 . 9 10 3 m K F = dE/dt A F = T 4 L = 4 R 2 F T = [(1 A ) / (2 or 4)] 1 / 4 ( R /d ) 1 / 2 T = (332 or 279 K)[(1 A ) /d 2 ] 1 / 4 V 2 esc = 2 GM/R V 2 rms = 3 kT/ V esc 6 V rms to retain gas F tide = 2 GMmR/d 3 R Roche = 2 . 4( M/m ) 1 / 3 r m = 2 . 4( M / m ) 1 / 3 R M n = n e t t 1 / 2 = ln 2 / NOTE: the above symbols may have dierent meanings in dierent equations!...
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This note was uploaded on 10/06/2011 for the course ASTRO 210 taught by Professor Fields during the Spring '08 term at University of Illinois, Urbana Champaign.

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