<strong>AP</strong> <strong>Physics</strong> <strong>Chapter</strong> <strong>33</strong> <strong>Self</strong>-<strong>Study</strong> <strong>Guide</strong> (<strong>Part</strong> 1) <strong>KEY</strong>1. Astrophysics2. Cosmology3. 9.46 x 10 151 ly = (3 x 10 8 m/s)(365.25 d/y)(24 h/d)(3600 s/h)= 9.47 x 10 15 m4. Milky Way5. galaxy6. 100,000 ly, 2000 ly, 10 11 , 28,000 ly, 200 millionyears7. Using data from #6:F = ma2GMm 4r m22r T2 34 rM 2GT215 34[(28,000ly)(9.46x10m/ly)]-11 3 267[6.67×10 m /(kg – s )][(200x10y)(3.156x10s/y)]= 2.76 x 10 41 kg8. From Earth, multiple pictures were taken of the entireMilky Way from multiple locations to see the wholething. It represents a view over 180 of sky, so it shouldbe viewed by wrapping it in a semicircle with your eyesat the center. Despite this, its resemblance to pictures ofother spiral galaxies (edge-on) is remarkable.9. cluster10. nebula, gas or dust, Hubble Space Telescope.11. telescopes, stars12. clusters, and superclusters (which are groups ofclusters)13. 2 x 10 614. When you look at far-away objects, the light takesmany years to travel here, so you are looking at theobjects as they existed many years ago.15. parallax16. 100tan 0.00006 = d/D = (1.5 x 10 8 km)/D17. minute (‘), second (“)18. pc, parallax angle in seconds of arctan (1/3600) = (1.5 x 10 11 m)/D1 pc = D = (3.09 x 10 16 m)(1 ly / 9.46 x 10 15 m) = 3.26 ly2NOTE: Similarly, 2 pc = 1.55 x 10 16 m. This is almostexactly twice the length of 1 pc, because for very smallangles, tan (2) 2 tan ().19. 1/0.22 = 4.5 pc20. brightness, star, same intrinsic luminosity.21. l, L, square, 4r 2 (but note that the text uses d insteadof r for the distance).22. 1/923. luminosity (and its temperature)24. black, temperature, frequency, wavelength25. 3500 K, 50,000 K, <strong>33</strong>-5, p T = 2.90 x 10 -3 mK26. Hertzsprung-Russell, absolute luminosity, surfacetemperature, sequence, giants, dwarfs27. No. Larger numbers are to the left.28. Stefan-Boltzmann, the temperature (in K) to the 4 thpower.29. gas, gravity, kinetic, Coulomb (i.e., electrostatic),fusion, hydrogen, helium, 10 7 K, 1 keV, K av = 3/2 kT30. hydrogen, hotter, expand, cooler, red, red giant,sequence, Earth31. Be and C, mass, Fe (or Ni – the text is not too clearabout this), require32. 1.4, Chandrasekhar, white dwarf, Earth,density = mass / volume= (1.99 x 10 30 kg)/ [(4/3) (6.37 x 10 8 cm) 3 ]= 1840 kg for 1 cm 3 (heavy stuff!)Pauli, exclusion<strong>33</strong>. iron (or nickel), protons and neutrons, protons,electrons, neutrinos (v), neutron, gravitational potential,periodic table, days, supernova. This is probably thesource of the heavier elements on Earth.34. China, Crab, 1054, SN1987a35. angular, increase, magnetic, charged, radiation,pulsar.36. 10 km,mass / volume = (1.5)(1.99 x 10 30 kg) / [(4/3)(5 km)] 3= (convert 5 km to 500,000 cm) …= 3.25 x 10 11 kg per cm 3 (whoa!!)37. gravitational, c, black hole, galaxy