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.
The scientific method is a method of investigation involving experimentation and observation to acquire new knowledge, solve problems, and answer questions. The key steps in the scientific method include the following: Step 1: Make observations. Step 2: Formulate a hypothesis.
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Answer:
Warm, Dry
Explanation: It is on the side where rain does not come very often.
Answer:
This statement is true
Explanation:
Cellular respiration uses the ingredients of glucose and oxygen to create water along with energy and carbon dioxide. However, for photosynthesis, it is the opposite. In photosynthesis water, energy, and carbon dioxide are the ingredients needed to produce to reactants of glucose and oxygen. Hope this helps!
Answer:
tensional
Explanation:
Tensional stress, meaning rocks pulling apart from each other, creates a normal fault.