how does the gravitational force exerted by earth on the sun compare with the gravitational force exerted by sun on the earth?
and
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
To determine how the gravitational force exerted by Earth on the Sun compares with the gravitational force exerted by the Sun on Earth, we can use Newton's law of universal gravitation. The law states that the gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
First, let's consider the mass of the Sun and the mass of Earth. The mass of the Sun is approximately 333,000 times greater than the mass of Earth. This means the Sun's gravitational force on Earth is much stronger than Earth's gravitational force on the Sun due to the larger mass of the Sun.
Now, let's consider the distance between the Sun and Earth. On average, the distance between the Sun and Earth is about 93 million miles (or 150 million kilometers). Since the distance between the Sun and Earth is the same for both gravitational forces, it does not affect their ratio.
Therefore, overall, the gravitational force exerted by the Sun on Earth is about 333,000 times greater than the gravitational force exerted by Earth on the Sun.
Moving on to the second question about tides, tides are primarily caused by the gravitational interaction between Earth, the Moon, and the Sun. The Moon has a greater influence on tides since it is closer to Earth than the Sun.
Tides occur due to the difference in gravitational force between the side of the Earth facing the Moon and the side opposite the Moon. This gravitational force creates a tidal bulge on both sides of the Earth, resulting in high tides.
Considering the effect of tides at the equator and the North Pole, we have to consider the Earth's rotation. The equator experiences higher tides compared to the North Pole. This is because the rotation of the Earth causes a centrifugal force that counteracts the gravitational force of the Moon. At the equator, the centrifugal force is greatest, leading to a higher tidal bulge. In contrast, at the North Pole, the centrifugal force is virtually negligible, resulting in lower tides.
So, in summary, the tides are generally higher at the equator compared to the North Pole due to the combined influence of the Moon's gravitational force and the centrifugal force caused by the Earth's rotation.