Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space?
A) The cloud is cool and lies between you and a hot star.
B) The cloud is extremely hot.
C) The cloud is visible primarily because it reflects light from nearby stars.
D) The cloud is cool and dense, so that you cannot see any objects that lie behind it.
A) The cloud is cool and lies between you and a hot star.
You might also like to view...
Power: If the voltage across a circuit of constant resistance is doubled, the power dissipated by that circuit will
A. be four times as large. B. be two times as large. C. decrease to one-half the original power. D. decrease to one-fourth the original power.
Humans’ specific day-night rhythms
A. Circadian Rhythm
B. Glare
C. Vincent Van Gogh
D. International Dark-Sky Association
E. Shielding
F. Sky Glow
Your car gets 34.7 mi/gal on a vacation trip in the U.S. If you were figuring your mileage in Europe, how many km/L did it get? (3.79 L = 1.00 gal; 1.00 mi = 1.61 km)
A) 14.7 km/L B) 9.16 km/L C) 55.9 km/L D) 32.4 km/L
A string that is 0.26 m long is vibrating in its n = 6 harmonic. The sound from this string excites a pipe that is long and open at both ends into its second overtone resonance
What is the common resonant frequency of the string and the pipe? The speed of sound in air is 345 m/s. A) 760 Hz B) 690 Hz C) 390 Hz D) 490 Hz E) 590 Hz