Understanding Buoyancy: The Role of Object Shape and Archimedes' Principle

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Discussion Overview

The discussion revolves around the concept of buoyancy, specifically examining the role of object shape and Archimedes' Principle. Participants explore how these factors influence whether an object floats or sinks in a fluid, addressing theoretical and conceptual aspects of buoyancy.

Discussion Character

  • Conceptual clarification
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants assert that the buoyant force acting on an object depends on the volume of fluid displaced, not the shape of the object.
  • Others argue that whether an object floats is determined by the comparison of the buoyant force to the weight of the object.
  • A participant suggests that the condition for floating can be expressed in terms of density, stating that if the object's density is less than that of the fluid, it will float.
  • There is a contention regarding the relevance of weight versus density in determining buoyancy, with some emphasizing the importance of weight while others highlight density.
  • One participant notes the potential confusion when applying density concepts to objects with nonuniform density, such as ships.
  • Another participant expresses confusion regarding the relationship between weight and buoyancy, using the example of a ship versus a solid block of steel to illustrate their point.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best way to articulate the conditions for floating, with multiple competing views on the relevance of weight versus density in buoyancy discussions.

Contextual Notes

Some statements rely on assumptions about uniformity in density and do not address the complexities introduced by nonuniform density objects. The discussion also reflects varying interpretations of Archimedes' Principle.

mreccentric
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I had read that, according to Law of Buoyancy/Archimedes Principle,
"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."

But does that depend on the shape of the object immersed? I see, that a metal block doesn't float when it's immersed in water. Please help me understanding this.
 
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mreccentric said:
But does that depend on the shape of the object immersed?
No, just on the volume of fluid displaced.
I see, that a metal block doesn't float when it's immersed in water.
Whether an object floats or not depends on how the buoyant force compares to the weight of the object. If the buoyant force is enough to counter the weight of the object, then it will float.

If you submerge two identically shaped and sized blocks under water, the upward buoyant force on each is the same even though one might be wood and the other metal.
 
Whether an object floats or not depends on how the buoyant force compares to the weight of the object. If the buoyant force is enough to counter the weight of the object, then it will float.
It's compared to it's density not it's weight.
 
Buckleymanor said:
It's compared to it's density not it's weight.
No, the buoyant force must be compared to the weight of the object.

You could express the condition for floating in terms of density: If the density of the object is less than the density of the fluid, then it will float. Which is a perfectly fine way to look at it. (Equivalent, of course.)
 
Using density can be confusing for objects of nonuniform density, like ships.
 
What's confusing about it if you just consider the overall density.Weight is where I get confused a ship weighing 10 ton floats a ten ton block of steel sinks.
 
You could express the condition for floating in terms of density: If the density of the object is less than the density of the fluid, then it will float. Which is a perfectly fine way to look at it. (Equivalent, of course.)
Yes, which was what I was trying to say but without explaining the buoyant force.If the overall density of the object is less than the fluid it is submerged in then the object floats if it's more it sinks.
If the object floats the amount of fluid it displaces is equivalent to it's own weight.
 

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