Water displaced against surface area

Click For Summary

Discussion Overview

The discussion revolves around the relationship between the volume of submerged objects and their surface areas, particularly in the context of water displacement. Participants explore whether two objects that displace the same volume of water necessarily have the same surface area, using examples of differently shaped objects such as cuboids and spheres.

Discussion Character

  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants propose that two objects of the same volume may not have the same surface area, as illustrated by the example of two cuboids with the same volume but different surface areas.
  • One participant mentions the specific application of calculating the surface area of a ship's hull based on its water displacement, noting that hull shapes vary according to vessel application.
  • Another participant argues that water displacement is not related to surface area, using the example of a steel-wool pad versus a steel sphere of equal volume to illustrate this point.
  • There is a reiteration of the initial question regarding whether differently shaped objects that displace the same volume of water will have the same surface area, with a participant asserting that the answer is no.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the relationship between volume and surface area. Multiple competing views remain, particularly regarding the relevance of surface area to water displacement.

Contextual Notes

Some calculations and assumptions regarding surface area and volume are not fully explored, and the discussion highlights the complexity of the relationship between shape, volume, and surface area.

nextar
Messages
3
Reaction score
0
If 2 differently shaped objects are submerged in water, say one is rectangular and other spherical, and both displaces the same volume of water, would the surface area of both objects be the same?
 
Physics news on Phys.org
I don't see how water is relevant here.

Basically you are asking if two objects of the same volume have the same surface.

Let's see - calculate volume and surface of two cuboids. One 3x3x3 and the other 1x1x27.
 
Thanks, what is given actually is the water displacement of a ship and I must find out the surface area of the hull below waterline. But hull shapes design vary according to vessel application. So what you're saying is surface area can be computed given the water displacement of the hull regardless of its shape.
 
Last edited:
What I am saying is try to calculate volume and surface of two given cuboids. Do it.

--
methods
 
cuboids 3x3x3 and 1x1x27 have the same volume but different surface areas. check your math
 
if 2 differently shaped objects are submerged in water, say one is rectangular and other spherical, and both displaces the same volume of water, would the surface area of both objects be the same?

no...
 
nextar said:
cuboids 3x3x3 and 1x1x27 have the same volume but different surface areas. check your math

I have never said they have identical surface & volume. However, now you should be able to answer your question from the very first post:

nextar said:
If 2 differently shaped objects (...) displace the same volume of water, would the surface area of both objects be the same?
 
Consider the huge surface area of a steel-wool pad. It will displace much less water than a steel sphere of equal volume. Water displacement is *not* related to surface area.
 
twang said:
Consider the huge surface area of a steel-wool pad. It will displace much less water than a steel sphere of equal volume.

Define surface area of steel-wool pad.
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 40 ·
2
Replies
40
Views
4K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 36 ·
2
Replies
36
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 12 ·
Replies
12
Views
7K
  • · Replies 7 ·
Replies
7
Views
2K