Answer:
25 meters per second
Explanation:
2 halves so you find the average of the two by adding 20+30=50 then dividing it by number of halves, this is 2.
50/2=25
-- <em>Mechanical waves DO</em> require a medium in order to travel from place to place. (Sound can't travel without some material to travel through on the way.)
-- <em>Electromagnetic waves do NOT</em> need a medium in order to travel from place to place. (Sunlight reaches us from the Sun without anything to travel through on the way.)
The correct answer is "True."
Further Explanation:
When a person first sees someone they are interested in they may have feelings of infatuation. When a person feels this they may believe it is love, but it is a significant level of the dopamine and norepinephrine that is being released into the brain.
After a while, when the infatuation subsides, the person may not have the same feelings as before since the levels have subsided. These substances control several emotions in the brain such as cravings for food, desires, and even a person's motivation.
Learn more about dopamine at brainly.com/question/3552597
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