Tides3 - The bulges actually occur on both sides of the...

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Tides You may have noticed that I used the phrase "tidally locked" above. What's that all about? Living in Iowa, you are probably not too familiar with the phenomena of tides, and just to be clear, I'm not referring to laundry detergent - what I'm talking about is how the Moon and the Earth pull upon one another and how the consequences of those "pulls" are predictable. Tides usually refer to the water levels of large bodies of water like the oceans which change near the shore due to the pull of the Moon (and the Sun) on the water. While we haven't gotten to gravity yet, you can at least appreciate the fact that a large nearby object like the Moon has a pretty good gravitational influence on the Earth - it is pulling on the Earth all the time, but the only thing that we see responding to the pull is the water. This gravitational pull causes a bulge in the water in the oceans. This bulge follows the motion of the Moon.
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Unformatted text preview: The bulges actually occur on both sides of the Earth. The side that's closest to the Moon feels the strongest pull and bulges out, and the side furthest from the Moon feels a lesser pull and is sort of left behind (since the center of the Earth also feels the pull, more than the water on the furthest side of the Earth). This is shown in Figure 12. Figure 12. The Moon's pull on the water and the Earth produces bulges on the two sides of the Earth. The degree of the pull is shown by the arrows, with the side nearer the Moon having the largest pull, and the side further having the smallest pull. Since it takes only 23 hours and 56 minutes for the Earth to rotate, coastal locations will pass through the high water bulges (have high tides) two times each day. Remember, the motion of the Moon is much slower, so the Earth actually rotates through the tides....
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