This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Why is it surprising that spiral arms are stable structures, lasting billions of years? a. ... (Read 35 times)

codyclark

  • Hero Member
  • *****
  • Posts: 538
on: Jul 27, 2018
Why is it surprising that spiral arms are stable structures, lasting billions of years?
 
  a. Differential rotation should tear the arms apart.
 b. Gas and dust clouds should run out of material to make young stars.
  c. Supernova explosions should disrupt the arms.
 d. Globular clusters are continuously passing through the arms.
 e. Gravity should pull the arms down into the center of the galaxy.

Question 2

According to the theory of general relativity, gravity is caused by the ____.
 
  a. linear motion of stars
 b. change in mass of a moving body
  c. curvature of space-time
 d. constant speed of light
 e. inertia of a moving body


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

jaymee143

  • Sr. Member
  • ****
  • Posts: 341
Reply #1 on: Jul 27, 2018
Answer to Question 1

a

Answer to Question 2

c


codyclark

  • Member
  • Posts: 538
Reply 2 on: Jul 27, 2018
Excellent

amcvicar

  • Member
  • Posts: 341
Reply 3 on: Yesterday
Gracias!

« previous next »
 

Did you know?

Although the Roman numeral for the number 4 has always been taught to have been "IV," according to historians, the ancient Romans probably used "IIII" most of the time. This is partially backed up by the fact that early grandfather clocks displayed IIII for the number 4 instead of IV. Early clockmakers apparently thought that the IIII balanced out the VIII (used for the number 8) on the clock face and that it just looked better.

Did you know?

The Romans did not use numerals to indicate fractions but instead used words to indicate parts of a whole.

Did you know?

This year, an estimated 1.4 million Americans will have a new or recurrent heart attack.

Did you know?

The senior population grows every year. Seniors older than 65 years of age now comprise more than 13% of the total population. However, women outlive men. In the 85-and-over age group, there are only 45 men to every 100 women.

Did you know?

It is important to read food labels and choose foods with low cholesterol and saturated trans fat. You should limit saturated fat to no higher than 6% of daily calories.

Discipline-specific training can take years to perfect. Discipline-specific training can take years to perfect.
Identify the structures shown below by filling in the blanks. Identify the structures shown below by filling in the blanks.
Chemical structures of ester and amide local anesthetics Chemical structures of ester and amide local anesthetics
Abdominal vasculature and deep structures Abdominal vasculature and deep structures
Major Structures of the Human Brain Major Structures of the Human Brain
Beak size in finches during dry years increases because of strong selection Beak size in finches during dry years increases because of strong selection
Video: Structures that affect circulation - kidneys, blood volume and venous tone

For a complete list of videos, visit our video library