posted by amar on .
how does the gravitational force exerted by earth on the sun compare with the gravitational force exerted by sun on the earth?
would you expect tides to be higher at the equator or at the north pole? why?
1) They are equal and opposite.
2) Which is closer to the Sun? North Pole or Equator?
They better be equal and opposite (third law)
water closer to sun at equator on daylight side, pulled away from earth/water center of gravity --> bulge on daytime side.
earth closer to sun than water at equator on nighttime side, earth pulled out from under water-->bulge on night side.
Thus high tide every 12 hours approximately.
Water above CG of earth at poles, no tidal force pulling earth away from water or water away from earth.
The equator has higher tides because of the larger difference between the sun's (and moon's) pull on opposite sides. (One side is closer and the other is father away) This causes the ocean's surface to have an oblate spheroidal shape, making the tides higher nearer the equator