Answer:
1. A
2. One side of the Earth is facing the sun, while another isn't.
3. The Earth is tilted on it's axis which is how we experience seasons.
4. 2 since it's directly across from the sun but is still facing the sun.
5. The Northern hemisphere since the intensity of the sun is slightly greater than 3.
6. Michigan experiences Winter while Argentina experiences Summer because they are on the opposite sides of the world. Argentina has the most intensity of light from the sun compared to Michigan, the seasons rely on the tilt of the Earth on it's axis.
Explanation:
Answer:
b. flat rotation curves in spiral galaxies
Explanation:
Dark matter accounts for majority of the matter in the universe (about 85%). It is considered to be composed of subatomic particles which are yet to be discovered. Dark matter cannot be observed because it does not emit light that can be detected. Only its gravitational effect is visible.
Astronomers when calculated the mass of the visible matter and tried to account for the observed speed of stars in the galaxy, there was a mismatch. To understand what caused this mismatch, astronomers gave name to the invisible matter as the Dark Matter.
The expected velocity of stars should decrease away from the near the center of the galaxy but a constant velocity of stars was observed that is a relatively flat rotation curve was obtained.
Thus, flat rotation curves in spiral galaxies in an evidence of Dark Matter.
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B. In the twentieth century alone, the world population grew by more than 5 billion people.
C. Population grew slowly until the eighteenth century because death rates were higher.
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- Hannah ❤
The chronometer is a device to measure time in a period of time, therefore not a correct answer.
