The right ascensions and declinations of stars stay approximately but not perfectly constant with time. What causes these coordinates to gradually change, enough to be noticeable with telescopes in just a few decades?
A) the precession of Earth's axis
B) changes in Earth's orbit around the Sun
C) tidal effects of the Moon
D) the motions of stars relative to the Sun
A) the precession of Earth's axis
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On the scale of the cosmic calendar, in which the history of the universe is compressed to 1 year, when did the Sun and Earth form?
A) January B) December C) September D) February
The distinguishing feature of a starburst galaxy is
A) the presence of an unusually large number of binary star systems containing X-ray bursters. B) a very large luminosity compared to the total luminosity of the Milky Way. C) strong radio emission from "lobes" of material well outside the visible boundaries of the galaxy. D) a rate of star formation that may be 100 or more times greater than that in the Milky Way.
State and explain Faraday's law of induction
What will be an ideal response?
An ideal gas occupies 6.00 × 102 cm3 at 20°C. At what temperature will it occupy 1.20 × 103 cm3 if the pressure is held constant?
A) 10°C B) 40°C C) 100°C D) 313°C