So if I had a canoe floating in the water on earth it would sink lets

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Discussion Overview

The discussion revolves around the behavior of a canoe floating in water under different gravitational fields, specifically comparing Earth and the Moon, and considering extreme gravitational environments like Jupiter. Participants explore concepts related to buoyancy, Archimedes' principle, and the effects of varying gravitational strengths on floating objects.

Discussion Character

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

Main Points Raised

  • One participant proposes that a canoe would sink the same depth in water on both Earth and the Moon, assuming the same mass and conditions.
  • Another participant introduces Archimedes' principle, emphasizing that the buoyant force is equal to the weight of the fluid displaced, which depends on gravitational field strength.
  • A participant questions whether extreme gravitational fields, like that of Jupiter, could lead to scenarios where a canoe might be pulled in or crushed.
  • Some participants argue that the gravitational field strength does not affect the buoyancy of the canoe, as both the canoe and the water experience the same gravitational force, maintaining the same floating level.
  • One participant suggests using the equivalence principle to illustrate that acceleration affects all bodies uniformly, supporting the idea that the float level remains unchanged.

Areas of Agreement / Disagreement

Participants express differing views on the impact of gravitational strength on buoyancy and floating behavior. While some assert that buoyancy remains constant across different gravitational fields, others speculate about extreme cases where this might not hold true. The discussion does not reach a consensus.

Contextual Notes

Participants reference Archimedes' principle and the equivalence principle, but there are unresolved assumptions regarding the effects of extreme gravitational fields and the conditions under which the canoe's behavior might change.

cragar
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So if I had a canoe floating in the water on Earth it would sink let's say 4 inches down. Now I take that same canoe with the same mass and put it in a lake on the moon, suppose the moon had a lake . Wouldn't the canoe also sink 4 inches down on the moon . Assuming the canoe had the same mass and was in water both times. And I was wondering could their ever be a Gravitational field where it was strong enough to sink the canoe besides a black hole. Will the canoe sink the same depth in all G fields.
 
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What happens when bodies float? Apply Archimedes principle here.
 


Continuing on from SteamKing, Archimedes' Principle is "Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object."

Note the word "weight", which is mass times gravitational field strength.
 


ok i understand Archimedes principle, Suppose we had a really strong G field, like on Jupiter, Isn't Jupiter G field so strong that if a can was placed on its surface that it would be crushed. I am just wondering if there is some weird extreme case where it would pull the boat in, probably not though
 


I don't think the gravitational field strength would matter.
Weight of boat is buoyed up by a force equal to weight of fluid displaced.
So W_boat = W_water.
Since W = mg and g is same in both cases, m_boat = m_water.
In that case, there would never be a situation where the boat would be sunk. The water level outside the boat would probably always be at the same level.
 


The Gravitational force would not matter, because it is acting on not only your canoe-but on the water as well. Keep in mind that Buoyancy is the counter-force of gravity.
 


cragar said:
ok i understand Archimedes principle, Suppose we had a really strong G field, like on Jupiter, Isn't Jupiter G field so strong that if a can was placed on its surface that it would be crushed. I am just wondering if there is some weird extreme case where it would pull the boat in, probably not though
No, you missed what Archimedes principle says here: The weight of the canoe increases at exactly the same proportion as the weight of the water increases, so the canoe floats at exactly the same height/depth everywhere.
 


You can verify Watters post via a simple thought experiment:use the equivalence principle: accelerate a body of water with a canoe floating on top...F = Ma applies to all and the float level remains the same...
 


ok i get it, thanks for your posts
 

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