A mechanical wave<span> requires an initial energy input. Once this initial energy is added, the </span>wave travels through<span> the medium until all its energy is transferred.</span>
Answer:

Explanation:
As we know that the pressure inside the liquid level is given as

here we have

h = 10.9 km
also we know that

now we have


As the Earth rotates on it’s axis we perceive the sky differently depending on where we are. This is known as a day, where the Earths rotation controls the day/night cycle. As Earth orbits the sun our axis wobbles, thus at different times in the year different regions of the Earth can see different areas in the sky.
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