Yes, eg., when 2 bodies move in opposite directions
, the relative velocity of each is greater than the individual velocity of either
Answer:
option D
Explanation:
Sunspots are the spot that appears on the sun, this spot appears darker than the surrounding surface of the sun.
Sun magnetic field goes through a cycle and this cycle is called the Sunspot cycle. Every 11 years the magnetic field of the sun completely flips. This sunspot cycle affects activity on the surface of the sun.
Sunspot cycle is the pattern of solar activity where an average number of sunspot gradually increase and decrease.
Hence, the correct answer is option D
Answer: Carbon 14 and Uranium 238 are not used together to determine fossil ages.
Explanation:
Carbon 14 with a half life of 5,700 years can only be used to date fossils of approximately 50,000 years. Most fossils are thought to be much older than 50,000 years. Also most fossils no longer contain any Carbon. The fossilized remains have been mineralized where the original organic material has been replaced and turned into stones containing no carbon.
Uranium 238 has a half life of 4.5 billion years. Uranium can be used to date the age of the earth. If 50% of pure uranium' is left in a sample the sample is assumed to be 4.5 billion years old.( This is assuming that the original sample was 100% uranium and no Uranium 238 has been eroded or lost in 4.5 billion years old. If a fossil has only 25 % of the Uranium 238 the sample has an estimated age of 3.2 Billion years. This would be the estimated age of the earliest life or formation of fossils.
Note no fossils contain Uranium 238. Uranium 238 is only found in igneous or volcanic rocks. So no fossils can be dated directly using U 238.
Because of the huge differences in the half lives of Carbon 14 and Uranium238 they cannot be used together. Carbon 14 can only be used to date fossils of a very recent age. Uranium 238 can only be used to date volcanic rocks of a very old age.
The tilt of the moon's axis does not allow for monthly alignment, so the lunar and solar eclipse do not happen every month.
<h3>How do the lunar and solar eclipse occur?</h3>
- For the occurrence of lunar and solar eclipse, the sun, moon and the earth must remain in a plan and along a straight line.
- When the earth appears in between the sun and the moon, lunar eclipse occurs.
- When the moon appears in between the sun and the earth, solar eclipse occurs.
- The moon and earth are rotating not only around the sun, but also around the black hole of Milky way galaxy.
- So they are not present in a plan as well as in a straight line in every full moon and new moon time.
Thus, we can conclude that the option D is correct.
Learn more about the lunar eclipse and solar eclipse here:
brainly.com/question/8643
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