How to Determine if Temperature Increase is Due to Work or Heat?

  • Context: Undergrad 
  • Thread starter Thread starter pardesi
  • Start date Start date
  • Tags Tags
    Heat Work Work done
Click For Summary

Discussion Overview

The discussion revolves around determining whether an increase in temperature in a system is due to work done on the system or heat released. It explores theoretical scenarios involving shaking water in a thermally insulated container and the movement of a block connected to a paddle in water, examining the underlying principles of thermodynamics.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions how to determine if the temperature increase in a system is due to work or heat, using the example of shaking water in a thermally insulated container.
  • Another participant asserts that once energy is in the form of heat, the method of generation is irrelevant.
  • A third participant references their textbook, claiming that the temperature increase is due to work done rather than heat generated.
  • One participant explains that heat flow requires a temperature difference and states that the increase in temperature from shaking the water is due to work done.
  • Several participants suggest that in the case of a paddle immersed in water connected to a movable block, the temperature rise is also due to work done, citing similar reasoning as in the previous example.
  • One participant notes that the paddle experiment was historically significant in demonstrating the conversion of mechanical work to heat.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between work and heat in causing temperature increases, with some asserting that the increase is due to work done while others reference different interpretations from textbooks. The discussion remains unresolved with multiple competing views present.

Contextual Notes

Participants reference specific scenarios and principles of thermodynamics, but there are unresolved assumptions regarding definitions of work and heat, as well as the conditions under which temperature increases occur.

pardesi
Messages
337
Reaction score
0
suppose a certain process is carried out on a system which say heats up the system the how do we decide that that's due to work done or heat released.
for example suppose i put water in an thermally insulated container and shake it and it's temp. increases then is it due to heat or work done
 
Science news on Phys.org
Once the energy is in the form of heat there is no difference in how the heat was initially generated.
 
but my book says it's work done and not heat generated
 
Heat flow requires a temperature difference. The issue is not "is thermal energy increased?"--of course it is. You can increase internal energy by doing work or by adding "heat". When you shake the water bottle, the increase in temperature is due to the work you've done.
 
yes this is what i thought.Also what about this case
there is a paddle immersed in water fixed within which is connected to a movable block through a fixed pulley When the block moves the temp of the system rises is it work done or heat released .I think work done because the same reason as above .
Would like to know ur answers
 
pardesi said:
Also what about this case
there is a paddle immersed in water fixed within which is connected to a movable block through a fixed pulley When the block moves the temp of the system rises is it work done or heat released .I think work done because the same reason as above .
Would like to know ur answers
Sure, that's a similar situation: the temperature increase is due to work done, not "heat" added. In fact, that paddle experiment was used by Joule to first show that mechanical work can be converted to "heat".
 

Similar threads

  • · Replies 27 ·
Replies
27
Views
7K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 15 ·
Replies
15
Views
4K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 23 ·
Replies
23
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K