Transcript qwk9
Pop-quiz #16 Which of the following statements is TRUE? A. Kepler’s 2nd law states that the orbits of planets are ellipses with the Sun at one of two foci of the ellipse B. Kepler’s 3rd law states that the square of the orbital period is proportional to the cube of the orbital radius C. Kepler’s laws apply only to the motion of planets in our Solar System D. Kepler’s 1st law states that the orbit of a planet around the Sun sweeps out equal areas in equal times Pop-quiz #17 Which of the following statements is FALSE? A. The total energy per second radiated by a black body is proportional to the fourth power of its temperature in Kelvin B. The peak wavelength at which a blackbody radiates becomes shorter as the temperature of the blackbody increases C. The spectrum of a typical active galaxy is well approximated by a black body spectrum D. The radiation from stars is well approximated by black body radiation Pop-quiz #18 Which of the following statements about the FINGER OF GOD effect is FALSE? A. It is a result of an incorrect assumption that the recession velocity of all galaxies is purely a result of Hubble expansion B. It is caused by peculiar velocities C. It is the result of local gravitational influences D. It is an actual alignment of galaxies in a line pointing towards the observer Pop-quiz #19 Which of the following statements about the nature of ELECTROMAGNETIC RADIATION is FALSE? A. It can be described as a wave of oscillating electric and magnetic fields and obeys the law: c = λν B. It can be described as “particles” of energy (photons) that obey the law: E = hν C. The earth’s atmosphere is transparent to all forms of electromagnetic radiation D. It travels at 300,000 km/s through vacuum E. It can be converted to matter and vice versa following the equation: E = mc2 Pop-quiz #20 Which of the following statements is FALSE? A. The Michelson-Morley experiment established that light is bent in a strong gravitational field B. Einstein received the Nobel Prize in Physics for explaining the photo-electric effect and the “particle” (photon) nature of light given by the law: E = hν C. Kepler’s laws can be used to describe the motion of planets around the Sun D. Hubble is credited with the discovery of the expansion of the Universe E. Guth and Linde formulated the theory of Inflation Pop-quiz #21 Which of the following statements is FALSE? A. Accretion disks and bi-polar jets are features associated with both star formation and active galactic nuclei B. Hayashi tracks describe the evolution of a star on the HR diagram after it has started nuclear fusion C. New stars in the Milky Way are born as a result of the gravitational collapse of giant molecular clouds and this often happens in the spiral arms D. High mass stars on the ZAMS have larger radii than lower mass stars E. A low mass proto-star’s temperature increases only slightly on its way to becoming a star but it’s radius shrinks by a large factor