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

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Discussion Overview

The discussion centers around the question of how the Moon's gravitational force can influence Earth's tides despite the Earth's significantly greater mass and gravitational pull. Participants explore the mechanics of tidal forces, the interaction between the Earth and Moon, and the implications of gravitational attraction in this context.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants note that while the Earth's gravitational pull is stronger, the Moon's gravitational influence creates a tidal force due to variations in gravitational strength across the Earth.
  • One participant suggests that the Moon causes a "sloshing effect" in the oceans rather than directly pulling water upwards.
  • Another participant emphasizes that the Earth's gravity ultimately keeps the water from escaping into space, indicating that the tidal forces do not overcome Earth's gravitational pull entirely.
  • Some participants raise questions about the Moon's increasing distance from the Earth, suggesting that the Moon's sideways motion prevents it from falling into the Earth and leads to its gradual outward spiral.
  • There is mention of the Earth's rotation affecting the alignment of tidal bulges, which in turn influences the Moon's orbit and distance from the Earth.

Areas of Agreement / Disagreement

Participants express various viewpoints on the mechanics of tides and the relationship between the Earth and Moon, with no clear consensus reached. Some agree on the role of tidal forces, while others question the implications of gravitational attraction and the Moon's orbit.

Contextual Notes

Participants discuss the complexities of gravitational interactions and tidal forces, but there are unresolved assumptions regarding the nature of these forces and their effects on the Earth-Moon system.

jaan
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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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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!
 
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.
 
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.
 
The Earth's gravity does win. The water does not shoot up into space.
 
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?
 
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.
 
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.
 

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