Which properties of spiral galaxies allow us to subclassify them as Sa, Sb, or Sc?
A) orientation
B) size of the disk
C) shape of the halo
D) size of bulge and extent of spiral arms
E) color of stars in the disk
Ans: D) size of bulge and extent of spiral arms
You might also like to view...
Most of the matter in our galaxy is in the
A) solid phase. B) liquid phase. C) gaseous phase. D) plasma phase. E) none of the above
An 8000-kg aluminum flagpole 100-m long is heated by the Sun from a temperature of 10°C to 20°C. Find the heat transferred (in J) to the aluminum if the specific heat of aluminum is 0.215 cal/g?°C.
A. 7.2 × 105 B. 7.2 × 107 C. 7.2 × 103 D. 7.2 × 101 E. 7.2 × 102
Which of the following statements about spectral types of stars is true?
A) The spectral type of a star can be used to determine its surface temperature. B) A star with spectral type A is cooler than a star with spectral type B. C) A star with spectral type F2 is hotter than a star with spectral type F3. D) The spectral type of a star can be used to determine its color. E) All of the above are true.
Two satellites are launched into circular orbits about the Earth. The one closer to the Earth has a period of 90 minutes. The one farther away will have a period which is ________ (longer than, shorter than, or the same as) 90 minutes.
Fill in the blank(s) with the appropriate word(s).