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Final Review. Final. Format 50 multiple choice questions 4 numerical Speed Stellar Lifetime t = 10 10 (M / L) Event Horizon R= 2GM/c 2 Hubble’s Law v = H d 46 general knowledge. Numerical Questions. Examples.
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Final • Format • 50 multiple choice questions • 4 numerical • Speed • Stellar Lifetime t = 1010 (M / L) • Event Horizon R= 2GM/c2 • Hubble’s Law v = H d • 46 general knowledge
Numerical Questions Examples
Assuming Viking 1 is 90 AU away from Earth, how long would a radio signal from it take to reach us? • How long would a star of 9 solar masses and 2700 solar luminosities remain on the main sequence? • What is the radius of a 32 solar mass black hole? • How far away, according to Hubble’s Law, is a galaxy that is moving away from us at 6000 km / sec?
Q 1 Distance = 90 AU = 90 AU x 1.5 x 108 km/AU = 9 x 1.5 x 109 km Time = Distance / Speed = 9 x 1.5 x 109 km / 3 x 105 km/s = 3 x 1.5 x 104 s = 4.5 x 104 s Convert to hours or days, if necessary. Hint: light takes 500 sec to travel 1 AU!
Q 2 Lifetime = 1010 (M / L) yr = 1010 (9 / 2700) yr = 1010 (1/300) yr = 103 x 107 / 300 yr = 3.3 x 107 yr = 33 million yr
Q 3 R = 2 G M / c2 Mass = 32 solar masses 1 solar mass black hole has a Schwarzschild radius of 3 km. Therefore, a 32 solar mass hole has a Schwarzschild radius of = 32x 3km = 96 km
Q 4 Hubble’s Law v = H d H = 21 km/s/Mly (70 km/sMpc) v = 6000 km/s Therefore, d = v / H = 6000 km/s / 21 km/s/Mly ~ 300 Mly
I • The Sky • Constellations • Ecliptic • Celestial equator and poles • Equinoxes and solstices • Forces and Motion • Galileo’s Observations • Kepler's Laws
II • Earth • Atmosphere • Mercury, Mars, Venus • Atmosphere • Main features • Jupiter, Saturn, Pluto • General properties
III • Light • Electromagnetic Spectrum • Wavelength, frequency, speed • Photons • Major Telescopes
IV • The Sun • Temperature (surface, core) • Composition • Power generation • Photons and neutrinos
V • Stars • Low to medium mass stars (like the Sun) • High-mass stars (like Betelgeuse) • White dwarfs • Red giants • Variable stars • Planetary nebulae • Neutron stars, pulsars, black holes
VI • Galaxies • Classification • The Milky Way • Globular clusters • Dark matter • Super-massive black holes
VII • Cosmology • Hubble's Law • Big Bang Theory • Cosmic Microwave Background • Life • Search for Extra Terrestrial Life