Surface Area of ball floating in water

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Discussion Overview

The discussion revolves around deriving a formula for the exposed surface area of a ball floating in water, considering factors such as water oscillations and the density of the ball. The scope includes mathematical reasoning and conceptual exploration of the problem.

Discussion Character

  • Exploratory, Mathematical reasoning, Conceptual clarification

Main Points Raised

  • One participant suggests using calculus to derive a formula for the exposed surface area, noting that the surface area of a sphere is \(A = 4\pi r^2\).
  • Another participant emphasizes that the density of the sphere is crucial for determining the exposed surface area and mentions that oscillations of the water will cause the ball to oscillate, but may not affect the surface area above water.
  • A further contribution highlights the variability of the exposed surface area due to water waves, stating that the ball could be fully submerged at times, leading to a range of exposed surface areas from maximum (placid water) to none (during rogue waves).
  • One participant proposes treating the problem as a surface of rotation to find a formula for the surface of a spherical cap.

Areas of Agreement / Disagreement

Participants express differing views on how water oscillations and density affect the exposed surface area, indicating that multiple competing perspectives remain without a consensus.

Contextual Notes

Limitations include the dependence on the density of the sphere and the assumptions regarding water oscillations and wave behavior, which are not fully resolved in the discussion.

Dustinsfl
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Using calculus, how would I derive a formula for the exposed surface area of a ball floating in water?

For such a formula to be a good candidate, it would have to consider oscillations of the water and placid water.

The surface area of a sphere is \(A = 4\pi r^2\).
 
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dwsmith said:
Using calculus, how would I derive a formula for the exposed surface area of a ball floating in water?

For such a formula to be a good candidate, it would have to consider oscillations of the water and placid water.

The surface area of a sphere is \(A = 4\pi r^2\).
That will depend upon the density of the sphere. And if the surface of the water oscillates, the ball will oscillate with it but I don't think that will change the amount of surface area above the water.
 
HallsofIvy said:
That will depend upon the density of the sphere. And if the surface of the water oscillates, the ball will oscillate with it but I don't think that will change the amount of surface area above the water.

Without knowing density, how could this be done?

If we think of waves, there are waves that entirely overtake objects floating in the water even if it is just for a moment. Therefore, there can be times that the ball is fully submerged. So the the amount above can be anywhere from the max (placid) to 0 rogue waves.
 
If I were to use the calculus, I would treat the problem as a surface of rotation, at least to find a formula for the surface of a spherical cap.
 

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