Is a 15kg object capable of generating 147N upward force in water?

  • Context: Undergrad 
  • Thread starter Thread starter malek340
  • Start date Start date
  • Tags Tags
    Buoyancy Water
Click For Summary

Discussion Overview

The discussion revolves around the calculation of buoyancy forces for a 15kg object submerged in water, specifically whether it can generate a target upward force of 147N. The scope includes theoretical calculations and practical applications related to buoyancy in water.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant proposes a formula for calculating buoyancy as the difference between the buoyancy force and the weight of the object, expressed as PVg - mg = upward force.
  • Another participant confirms the mathematical approach and provides a relatable comparison of the object's weight to that of two bowling balls.
  • A third participant clarifies that if "P" represents the mass density of water and "V" is the submerged volume, then the buoyancy force can be calculated as PVg, and emphasizes that for an object to float, the buoyancy force must equal the weight.
  • A later reply discusses practical experience in designing buoyant systems, suggesting a method of calculating buoyancy using volume in cubic feet and a specific weight of seawater, while noting the importance of accounting for material absorption.

Areas of Agreement / Disagreement

Participants generally agree on the principles of buoyancy calculations, but there is no consensus on the adequacy of the 147N target force for different types of objects, as some suggest it may be too high for smaller objects while too low for larger ones.

Contextual Notes

There are assumptions regarding the density of water and the volume of the object submerged that are not explicitly stated. The discussion does not resolve the applicability of the target force across different contexts.

Who May Find This Useful

Individuals interested in buoyancy calculations, engineering design of floating objects, or those working on projects involving submerged systems may find this discussion relevant.

malek340
Messages
34
Reaction score
0
I believe that the way to calculate buoyancy is buoyancy force-weight of object= upward force, which is PVg-mg= upward force. If I'm wrong please tell me. I set a target of 147N(15kg) upward force for my project product. Is it that strong? Give me your thoughts.
 
Physics news on Phys.org
Maths looks right.

15kG is about the weight of two Bowling balls.
 
If your "P" is the mass density of water and V is the volume of water of that part of the object below water, then, yes, the bouyancy force is PVg. The total force would be that minus the weight, mg. When the object is "floating", the two must cancel so that the total force is 0, neither up nor down.

As for a target bouyancy of 147 N, what is your question about it? For an icecube that would be much to high. For an ocean liner, it would be much too low!
 
I've designed many many buoyant systems for seawater. If figure volume in cubic feet and multiply by 60 lbf per cubic foot. The water is a little heavier than that, but I like the margins in case my material absorbs a little water.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 14 ·
Replies
14
Views
10K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 79 ·
3
Replies
79
Views
7K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 48 ·
2
Replies
48
Views
12K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 19 ·
Replies
19
Views
3K