Why Does Moon's Gravitational Force Overcome Earth's?

In summary: So although the Earth's gravity does have a stronger pull on the water, the Moon's gravitational pull creates a tidal force that causes the water to rise and fall, resulting in tides. The Moon's orbit also gradually gets further away from the Earth due to this interaction of tidal forces, causing the appogee and paragee to expand.
  • #1
jaan
6
0
This question was asked by a Std 9 student, and has me foxed.
Since the Earth is so much more massive than the moon, and its centre much closer to the surface, isn't the Earth's pull on the water much stronger than the moon's? Then how is it that the moon can cause Earth's water to rise to form tides, even overcoming the Earth's much larger force of attraction, which should prevent the waters from rising?
Any answers?
 
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  • #2
The tides are caused because the moon pulls on the water, but the Earth pulls stronger, that's why the water stays on the Earth. I understand what you are confused about, but don't know how to unconfuse you!
 
  • #3
The lunar tides are caused by difference in the moon's gravitational pull on the Earth at various points. (The force per unit mass is stronger nearest the moon, weakest away from the moon.) That variation in gravitational strength causes a stretching force called the tidal force; the effect of which is most readily seen in the oceans, which can flow.

Yes, the Earth's pull on the water is great, so the tidal force doesn't just strip off the oceans into space. But the water does get pulled away from the Earth a bit at the ends furthest and nearest to the moon, creating the tides.
 
  • #4
jaan said:
This question was asked by a Std 9 student, and has me foxed.
Since the Earth is so much more massive than the moon, and its centre much closer to the surface, isn't the Earth's pull on the water much stronger than the moon's? Then how is it that the moon can cause Earth's water to rise to form tides, even overcoming the Earth's much larger force of attraction, which should prevent the waters from rising?
Any answers?

think of it like this, the moon doesn't actually cause the water levels to go up and down, it causes more of a sloshing effect with the ocean.
 
  • #5
The Earth's gravity does win. The water does not shoot up into space.
 
  • #6
Here's one to chew on.

I already know the answer to this one.

If the Earth and the Moon both have gravitational attraction then why is the Moon getting further away from the Earth every time it orbits, the appogee and paragee is expanding its diameter every orbit around the Earth.

Why isn't the Moon falling into Earth's Gravity well instead of leaving it?
 
  • #7
gravity causes the moon to roll into the earth. but the moon is also travling sideways at just a slightly higher pace than it falls. so it keeps missing the earth. and slowly but surly it will icrease the diffrence as the sideways distance extends.
 
  • #8
OnTheCuttingEdge2005 said:
If the Earth and the Moon both have gravitational attraction then why is the Moon getting further away from the Earth every time it orbits, the appogee and paragee is expanding its diameter every orbit around the Earth.
Due to the Earth's rotation, the tidal bulges are not directly aligned with the Moon-Earth axis. The Moon's gravity acting on those bulges creates a torque on the Earth, slowing it; the pull of those bulges on the Moon speeds the Moon's orbit, causing it to spiral outward.
 

1. Why does the Moon's gravitational force overcome Earth's?

The Moon's gravitational force is able to overcome Earth's because of its smaller mass and closer proximity to Earth. Despite having a much smaller mass than Earth, the Moon is able to exert a significant gravitational force due to its close distance. This force is able to pull objects towards it, and because the Moon is also orbiting Earth, this creates the familiar phenomenon of tides.

2. How does the Moon's gravitational force affect the Earth?

The Moon's gravitational force has several effects on Earth. The most noticeable is the creation of ocean tides, which are caused by the Moon's gravitational pull on Earth's oceans. Additionally, the Moon's gravity affects the Earth's rotation, slowing it down by about 0.002 seconds per century. The Moon also stabilizes Earth's axial tilt, which helps to create a stable climate for life.

3. Is the Moon's gravitational force always stronger than Earth's?

No, the Moon's gravitational force is not always stronger than Earth's. On average, the Moon's gravitational force is about one-sixth of Earth's. However, there are instances where the Moon's gravitational force can be slightly stronger, such as during a full moon when the Moon is closest to Earth in its orbit. But in general, Earth's larger mass results in a stronger gravitational force.

4. How does the Moon's gravitational force compare to other celestial bodies?

The Moon's gravitational force is relatively weak compared to other celestial bodies. For example, the Sun's gravitational force is 27 million times stronger than the Moon's. Jupiter, the largest planet in our solar system, has a gravitational force that is over 300 times stronger than the Moon's. However, the Moon's gravitational force is still significant enough to create effects on Earth, such as tides and the stabilization of Earth's tilt.

5. Can the Moon's gravitational force ever overcome Earth's completely?

No, the Moon's gravitational force will never be able to completely overcome Earth's. This is because Earth's larger mass ensures that its gravitational force will always be stronger. Even if the Moon were to somehow increase in mass, it would still not be able to overcome Earth's gravitational force. However, the Moon's gravitational force is still significant enough to create effects on Earth, as mentioned before.

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