Answer:![\frac{2}{3}](https://tex.z-dn.net/?f=%5Cfrac%7B2%7D%7B3%7D)
Explanation:
Given
Man takes 3 s while running along the sidewalk
and 15 s while running opposite to sidewalk
Let the speed of man and sidewalk be v and v_0 and distance between the two endpoints of sidewalk is x
Now
----------1
Also
----------2
Divide 1 & 2
![1=\frac{v+v_0}{5(v-v_0)}](https://tex.z-dn.net/?f=1%3D%5Cfrac%7Bv%2Bv_0%7D%7B5%28v-v_0%29%7D)
![5v-5v_0=v+v_0](https://tex.z-dn.net/?f=5v-5v_0%3Dv%2Bv_0)
![4v=6v_0](https://tex.z-dn.net/?f=4v%3D6v_0)
![\frac{v_0}{v}=\frac{2}{3}](https://tex.z-dn.net/?f=%5Cfrac%7Bv_0%7D%7Bv%7D%3D%5Cfrac%7B2%7D%7B3%7D)
The answer would be Exosphere because, there are 3 main regions that circulate oxygen through the Earths system, which are the Biosphere, Atmosphere, and the Lithosphere.
the cycle of the Moon through all its phases
Explanation:
The cycle of the Moon through all its phases is closely related to the unit of time that humans call month.
It takes 27 days for the moon to complete its orbit around the earth and this is equivalent to a month.
The moon is the earth's natural satellite and it revolves round it in every 27 days.
The moon passes through its different phases within this time period.
learn more:
Astronomy brainly.com/question/1316347
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