Answer:
1, 2 and 3 are correct yes
Explanation: XD
Answer: is constant
Explanation:
In order to analyze the velocity of the stars within a galaxy, the <u>galaxy rotation curves</u> (developed by the American astronomer Vera Rubin) are used. These graphs are elaborated as a scatter diagram in which the orbital velocity of the stars present in a galaxy is represented on the Y axis and the distance of these stars to the center of the galaxy on the X axis.
Thanks to this diagram, it has been possible to observe a characteristic behavior in the rotation speed of the stars (and gas) present in the galaxies, which differs from the rules of the orbital movement of the planetary systems postulated by Newton and Kepler.
This means that in these galaxy rotation curves it has been observed that the rotation speed of stars and gas is "constant", regardless of the distance to the center of the galaxy. This discrepancy and these results were then used to demonstrate the existence of dark matter in the universe.
Answer:
B
. Improvements in nutrition, sanitation, and health care cause death rates to fall in stage 2 of the demographic transition
Explanation:
- The epidemiologic transition occurs in medical geography and states that the changing population patterns in terms of fertility, life expectancy, and death can lead to causes of death.
- The second stage is viewed as the age of receding pandemics that states that due to the increase in medical aid and facilities. Morality progressively declines and the average life expectancy increases from 30 to 50 years.
Answer:
Grinding Glass Is your answer!
Explanation: