Where does a body weigh lightest?

  • Thread starter Thread starter johsun123
  • Start date Start date
  • Tags Tags
    Body
AI Thread Summary
A body weighs lightest in a fluid when the upthrust, or buoyant force, is highest, which occurs in cold water. The discussion highlights that cold oil is often given as the answer, but this is misleading since most oils are less dense than water and float on it. The buoyancy effect does not change a person's weight but provides an upward force that counteracts gravity. The consensus is that the original answer is incorrect, as cold water should provide the greatest buoyancy. Therefore, the correct understanding is that a body weighs lightest in cold water due to the higher upthrust.
johsun123
Messages
16
Reaction score
0

Homework Statement



Hot oil, Hot water, Cold Oil, Cold water

Homework Equations



Upthrust according to flotation principle

The Attempt at a Solution



It will weight lightest when Upthrust by the fluid is highest, which should be cold water.

Answer given was " cold oil".
 
Physics news on Phys.org
I think you're right and the answer is wrong. Oil floats on water because it's less dense.
 
Only some forms of oil are denser than water, and a person's body weight doesn't change because it's floating, it's just that buoyancing is providing some countering upwards force, which would make this a trick question.
 
This was not meant to be a trick question, I am sure.
 
Most types of oil float on water so pretty sure the given answer is wrong.
 
Thread 'Voltmeter readings for this circuit with switches'

Thread 'Voltmeter readings for this circuit with switches'

TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
View full post »
Thread 'Correct statement about a reservoir with an outlet pipe'

Thread 'Correct statement about a reservoir with an outlet pipe'

The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
View full post »

Similar threads

Water level before and after metling of ice cube
Replies
4
Views
2K
Calculate the resulatant downward force of a submarine on the seafloor
Replies
11
Views
3K
Find the weight of a partially submerged cylinder
Replies
25
Views
4K
Thermodynamics: phase change and latent heat problem
Replies
12
Views
3K
Upthrust/ how does the weight of a sphere change in water?
Replies
5
Views
3K
Upthrust vs Weight: Object Immersion in Fluids
Replies
2
Views
1K
Calculating Specific Gravity and Density of a Body
Replies
1
Views
2K
Simple coefficient of performance question
Replies
6
Views
1K
Harnessing Energy in an Engine: The Secrets of Thermodynamics
Replies
5
Views
2K
How Does Mixing Water in Different Sequences Affect Entropy Change?
Replies
18
Views
3K

Hot Threads

Recent Insights

Back
Top