How to Relate Densities, Height, and Time for a Sinking Solid?

Click For Summary

Discussion Overview

The discussion revolves around the relationship between the densities of a liquid and a solid, the height from which the solid is released, gravitational force, and the time taken for the solid to reach the surface of the liquid. Participants explore how these variables might be connected, particularly through dimensional analysis, while seeking guidance on how to approach the problem without providing direct answers.

Discussion Character

  • Exploratory
  • Technical explanation
  • Homework-related

Main Points Raised

  • One participant seeks help starting the problem, asking if there is an equation that relates height, densities, and time, and whether it involves the difference between forces acting on the solid and liquid.
  • Another participant suggests that the situation may involve buoyancy and mentions that the time taken for an object to move through a liquid depends on viscosity and shape, although this is later challenged.
  • A different participant emphasizes the need for dimensional analysis to relate time, height, densities, and gravitational acceleration, dismissing the relevance of viscosity and shape.
  • There is a request for a clearer description of the problem, indicating that the initial explanation may not be sufficient for others to provide help.
  • A later reply suggests that the thread may be more appropriate for the Homework Help forum, indicating that it resembles schoolwork and advising the original poster to follow a specific template.

Areas of Agreement / Disagreement

Participants express differing views on the relevance of viscosity and shape in the problem, with some insisting these factors are not necessary for the analysis. The discussion remains unresolved regarding the best approach to relate the variables involved.

Contextual Notes

Participants note the importance of providing a clear description and possibly a sketch of the problem to facilitate better assistance. There is an indication that the problem may be part of a homework assignment, which could influence the nature of the responses.

vampulski
It has been a long time since I have worked with this and I need help just starting out.

The problem involves the density of a liquid, the density of a solid, and the height where the solid will be released in the liquid, gravitational force, and the time it takes to reach the top of the liquid.

I don't want answers, I just need help starting with this. Is there any equation that relates height to these 2 densities and time? Does it involve taking the difference between 2 forces, liquid and solid?

Thank you in advance.
 
Last edited by a moderator:
Physics news on Phys.org
vampulski said:
It has been a long time since I have worked with this and I need help just starting out.

The problem involves the density of a liquid, the density of a solid, and the height where the solid will be released in the liquid, gravitational force, and the time it takes to reach the top of the liquid.

I don't want answers, I just need help starting with this. Is there any equation that relates height to these 2 densities and time? Does it involve taking the difference between 2 forces, liquid and solid?

Thank you in advance.
Welcome to the PF. :smile:

Can you post a sketch of the situation? Your description so far doesn't seem to completely describe the problem...

You can Upload the image of your sketch (PDF or JPG) bu using the UPLOAD button in the lower right.
 
It sounds like you are talking about buoyancy. Wikipedia has a decent article. https://en.wikipedia.org/wiki/Buoyancy

The time it takes for an object to move through liquid will also depend on the viscosity of the liquid and shape of the object.
 
Khashishi said:
It sounds like you are talking about buoyancy. Wikipedia has a decent article. https://en.wikipedia.org/wiki/Buoyancy

The time it takes for an object to move through liquid will also depend on the viscosity of the liquid and shape of the object.
It does not involve viscosity or shape of object, it just asks to do dimensional analysis to find equations that relate time to h(distance from object to surface), density of liquid, density of object, and g(gravity). I just need a start, maybe some equation(s) that can help relate these variables.
 
vampulski said:
I just need a start, maybe some equation(s) that can help relate these variables.

well as you were asked, please explain this more clearly, it doesn't make much sense ...

vampulski said:
The problem involves the density of a liquid, the density of a solid, and the height where the solid will be released in the liquid, gravitational force, and the time it takes to reach the top of the liquid.

people may be able to help you if you help them with a clearer description with drawingsDave
 
vampulski said:
It has been a long time since I have worked with this
vampulski said:
It does not involve viscosity or shape of object, it just asks to do dimensional analysis to find equations that relate time to h(distance from object to surface), density of liquid, density of object, and g(gravity).
This is starting to sound like schoolwork. Perhaps you should re-post in the Homework Help, Introductory Physics forum, and fill out the Template that you are provided there. Be sure to fill out the sections on the Relevant Equations, and show your Attempt at a Solution.

This obtuse thread in the general technical forums is now closed. Thanks everybody for trying to help.
 

Similar threads

High School Question about pressure of a liquid
  • · Replies 8 ·
Replies
8
Views
1K
Undergrad Effect of time on density distribution+shape of uniformly dense sphere
  • · Replies 58 ·
2
Replies
58
Views
4K
Undergrad Gravity machine force calculations assistance needed
  • · Replies 13 ·
Replies
13
Views
2K
Undergrad How to find the change in volume of a solid to a liquid
  • · Replies 3 ·
Replies
3
Views
2K
Why is solid density used in this thermodynamics problem?
  • · Replies 5 ·
Replies
5
Views
3K
Undergrad A gravity conundrum involving a solid cylinder
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad How to calculate the "weight" of this piece of metal?
  • · Replies 12 ·
Replies
12
Views
2K
Density of a solid and Clapeyron equation
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Velocity of liquid from bottom pinhole of closed container
  • · Replies 33 ·
2
Replies
33
Views
6K
Undergrad Capillary and liquid tension problem
  • · Replies 3 ·
Replies
3
Views
1K