What produces the 21-cm radio line that we can be used to map the Milky Way Galaxy?
A) ionized hydrogen
B) atomic hydrogen
C) helium
D) carbon monoxide
E) molecular hydrogen
B
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Capacitors of values 6.0 mF and 9.0 mF are connected in series to a 30.0 V power supply. What is the resulting potential difference across the 6.0 mF capacitor?
A. 30 V B. 18 V C. 12 V D. 6.0 V E. 3.0 V
In a volcanic eruption, 2km3 of mountain with a density of 1600 kg=m3 was lifted an average height of 513m.
(a) How much energy in joules was released in this eruption? (b) The energy released by thermonuclear bombs is measured in megatons of TNT, where 1 megaton of TNT = 4.2 * 10 15 J. Convert your answer for (a) to megatons of TNT.
What is a new moon?
a. The lunar phase in which the first quarter Moon approaches full moon b. The lunar phase in which Earth's shadow is cast on the Moon c. The lunar phase in which the Moon's shadow is cast on Earth d. The lunar phase in which sunlight illuminates only the far side of the Moon e. The lunar phase in which sunlight illuminates the Earth facing side of the Moon
If we have a new moon today, when we will have the next full moon?
A) in about 6 months B) in about 1 month C) in about 1 week D) in about 2 weeks