Cypress College ASTR 116 Homework
Astronomy 116, Homework CHAPTER 16 (A) Hubble's Law and Dark Matter.
Due:
Print Last, First Name and date on the small Scantron in INK. Print
your last name in BIG BLOCK letters on the back of the Scantron.
Use a No. 2 pencil to fill out Scantron. Read the chapter.
Look at the videos and simulations in the CD-ROM. Answer all True/False and
Fill in the Blank questions. Then answer the following questions
and turn in your Scantron only. Choose the best answer.
1. What does the Hubble Law measure?
- a) The rate of expansion of the universe.
- b) How galaxies are distributed in the universe.
- c) How light gets fainter with increasing distance.
- d) Light travels at a finite speed; we see objects the way they were
when the light left them, not the way they are when we make our observation.
2. A galaxy is observed to have a red shift which indicates a recession
speed of 150 km/s. Use 75 km/s/Mpc for Hubble's constant and determine
the distance to the galaxy in Mpc.
- a. 150
- b. 11,250
- c. 2
- d. 0.5
- e. none of these
3. A galaxy is at a distance of one billion light years. Which
of the following is true?
- a) We see the galaxy the way it will be in one billion years.
- b) We see the galaxy the way it was one billion years ago.
- c) We see the galaxy the way it was when the universe was one billion
years old.
- d) We see what our galaxy will be like in one billion years.
4. Quasars have their distances measured by what technique?
- a) Cepheids
- b) Tully-Fisher relation
- c) Supernovae
- d) parallax
- e) Hubble law
5. Very distant galaxies tend to be _____ and _____ irregular than nearby
galaxies.
- a) larger; more
- b) larger; less
- c) smaller; more
- d) smaller; less
6. Collisions between galaxies:
- a) Turn ellipticals into spirals.
- b) May cause bursts of star formation.
- c) Cause large numbers of stars to collide and explode.
- d) Never occur.
7. The lensing of a distant quasar is produced by _______ of a
foreground galaxy.
- a) all the matter and dark matter
- b) the nucleus
- c) an individual star
- d) all the black holes
- e) the magnetic field
8. (True/False) Galaxies formed about one billion years after
the beginning of the universe.
9. Why are supermassive galaxies often found at the cores of rich galaxy
clusters?
- a) Most of the matter forming the cluster fell into the center to
form one large galaxy.
- b) Such a large galaxy attracted smaller galaxies around it to form
a cluster.
- c) Large galaxies, passing a cluster, get captured into the center.
- d) They are the result of numerous galactic mergers; one galaxy growing
at the expense of others.
10. Observations of distant quasars indicates that the universe
contains _____ dark matter.
- a. little
- b. a lot of
- c. none of these, quasar observations give no information about
dark matter.
11. Galaxy evolution models suggest that galaxies evolve as follows
- a. normal elliptical -> quasar -> radio galaxy
- b. normal elliptical -> radio galaxy -> quasar
- c. quasar -> normal elliptical -> radio galaxy
- d. quasar -> radio galaxy -> normal elliptical