The oxygen in Earth's atmosphere
a. was manufactured inside stars.
b. was added to the atmosphere by plant life.
c. has grown more abundant since the origin of Earth.
d. all of these
e. none of these
D
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Neutron stars radiate most of their energy in the ____ wavelength band(s)
a. radio and infrared b. radio and X-ray c. visible d. visible and gamma-ray e. X-ray and gamma-ray
A 4.0-kg mass is placed at (3.0, 4.0) m, and a 7.0-kg mass is placed at (3.0, -4.0) m. What is the moment of inertia of this system of masses about the x axis?
a. 275 kg•m2 b. 90 kg•m2 c. 176 kg•m2 d. 99 kg•m2
Power: For the graph shown in the figure, what physical quantity does the slope of the graph represent for a dc circuit?
A. 1/(resistance) B. resistance C. potential D. (potential)2 E. 1/(potential)
We do not know for certain whether the general trends we observe in stellar birth masses also apply to brown dwarfs. But if they do, then which of the following would be true?
A) Brown dwarfs would outnumber all ordinary stars. B) Brown dwarfs would be responsible for most of the overall luminosity of our Milky Way Galaxy. C) Brown dwarfs would be extremely rare. D) Most of the brown dwarfs in the Milky Way Galaxy would be quite young in age.