Calculating Force of a 600ml Bottle Underwater

  • Context: High School 
  • Thread starter Thread starter bobcat19
  • Start date Start date
  • Tags Tags
    Water
Click For Summary

Discussion Overview

The discussion revolves around calculating the force exerted by a 600ml bottle when submerged underwater, particularly focusing on concepts of buoyancy and displacement. Participants explore the implications of the bottle being empty versus filled with different materials, such as sand.

Discussion Character

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

Main Points Raised

  • One participant inquires about the force exerted by an empty 600ml bottle underwater, linking it to the concept of displacement.
  • Another participant states that the upward buoyant force on the bottle equals the weight of the displaced water, referencing Archimedes's principle.
  • There is a claim that the bottle, being 600 cubic centimeters, should exert a force of approximately 600 grams.
  • Some participants agree with the initial claim about the force exerted by the bottle.
  • A question is raised regarding the scenario where the bottle is filled with sand, noting that it would still displace the same amount of water but would sink, prompting further exploration of the forces involved.
  • It is clarified that while the buoyant force remains the same, the weight of the bottle and its contents must also be considered, which affects whether it sinks or floats.
  • Another participant notes that if the density of the contents exceeds that of water, the bottle will sink, but it will weigh less underwater due to the buoyant force.
  • There is a correction regarding the force calculation, specifying that 600 grams corresponds to 5.89 Newtons or 5.89 x 10^5 dynes.

Areas of Agreement / Disagreement

Participants generally agree on the principles of buoyancy and displacement, but there are competing views regarding the implications of different contents in the bottle and the calculations of force. The discussion remains unresolved on some aspects, particularly regarding the weight calculations and their interpretations.

Contextual Notes

Participants express uncertainty about the relationship between the weight of the bottle's contents and the buoyant force, as well as the implications of different materials on the bottle's behavior underwater. There are also unresolved mathematical steps related to the conversion of grams to Newtons and dynes.

bobcat19
Messages
4
Reaction score
0
well today we were in the pool together and i had just finished a drink that id had(bottle of pepsi) and somehow we got talking about displacement, see what i want to know is how much force is that 600ml bottle is creating when its under then water(remembering that its empty)

i don't know anything about physics so nice simple terms would be nice but don't worry to much cause I am sure i can work it out

any help much appreciated

Alex
 
Physics news on Phys.org
The upward buoyant force that the water exerts on the bottle is equal to the weight of the displaced water. (That's Archimedes's principle.)
 
ok so because its about 600 cubic centimetres it should be exerting 600 grams or something like that.
 
Sounds right.
 
but hang on, what if the bottle was filled with sand, it would still displace the same amount of water but of course it would sink. how does that work?
 
bobcat19 said:
but hang on, what if the bottle was filled with sand, it would still displace the same amount of water but of course it would sink. how does that work?
The buoyant force that the water exerts on the bottle will be the same, but that's not the only force acting on the bottle. You must also consider the weight of the bottle (and contents), which acts downward. When filled with sand, the weight will be greater than the buoyant force and the bottle will sink.
 
ok i get it. thanks you've helped me a lot :)
 
Anytime the density of the contents is greater than the density of water, the bottle will sink...but if weighed underwater it weighs less than on land by the weight of water displaced.
 
bobcat19 said:
ok so because its about 600 cubic centimetres it should be exerting 600 grams or something like that.
Well, no. 600g dynes, the force of gravity on a mass of 600 grams.
 
  • #10
600 grams weighs about 5.89 Newtons or 5.89 x 105 dynes.
 

Similar threads

  • · Replies 123 ·
5
Replies
123
Views
7K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 10 ·
Replies
10
Views
4K
  • · Replies 8 ·
Replies
8
Views
15K
  • · Replies 12 ·
Replies
12
Views
5K
  • · Replies 21 ·
Replies
21
Views
7K