ASTR 001 Lecture Notes - Lecture 28: Tidal Acceleration, Moe Williams, Rubber Band
15 Jul 2020
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Document Summary
Attraction (gravitational force or gravity) is directly proportional to the product of their masses. Attraction is inversely proportional to the square of the distance between their centers. Application of newton"s law of gravitation: tides. Gravitational pull of the moon on earth decreases with distance. Moon"s gravity pulls harder on near side of earth than on far side. Tidal bulge #1 easy to understand that side of the earth will be pulled to the moon. Tidal bulge #2: water pulled away from the leftmost point. Low tide, high tide, low tide, high tide see diagram on slide. As earth rotates through the tidal bulges, it (land) tries to drat water bulges with it through land-water friction tidal friction. Net effects: tidal friction gradually slows earth"s rotation and makes moon get farther from earth. At present time the length of a day increases by 1 second every. Moon is moving away about 4 cm per year.
