Very quick entropy problem

  • Thread starter erjkism
  • Start date
  • #1
54
0
i was just wondering if the entropy increases or decreases when air is pumped into a tire. my guess is that it would decrease because the gas molecules would be closer together. am i correct?
 

Answers and Replies

  • #2
Danger
Gold Member
9,607
249
In a way, I suppose. Overall, the entropy has to increase, but that can be expressed by the heat released into the atmosphere by the compressor. I guess that it decreases inside the tire.
 
  • #3
dst
376
0
I'm guessing there's a gain in entropy inside the tire as well. Increasing the pressure is equivalent to increasing heat. On the other hand, the maximum number of positions occupiable by gas molecules has to decrease, but you aso have more gas molecules.

I'm sure this is a common question.
 
  • #4
Danger
Gold Member
9,607
249
I was kind of wondering about the heat issue as well, and I really don't know what to make of it. The molecules are more restricted in their range of motion, but they move faster. I don't know whether that counts as an increase, a decrease, or neutrality. :confused:
 
  • #5
dst
376
0
Sounds like neutrality to me. In a square box, any increase in no. molecules should surely be balanced out by the decrease in volume.
 
  • #6
54
0
what about just the inside of the tire. disregard the heat from the compressor, and instead consider the inside of a tire going from deflated to inflated.
 

Related Threads on Very quick entropy problem

  • Last Post
Replies
19
Views
6K
Replies
1
Views
2K
  • Last Post
Replies
13
Views
2K
  • Last Post
Replies
3
Views
2K
Replies
5
Views
5K
  • Last Post
Replies
4
Views
822
  • Last Post
Replies
7
Views
1K
Replies
15
Views
3K
  • Last Post
Replies
6
Views
1K
  • Last Post
Replies
4
Views
911
Top