Gen Physics HW Help: Ideal Gas Law and Temperature Change

  • Thread starter Thread starter pyizzle
  • Start date Start date
  • Tags Tags
    Homework Physics
AI Thread Summary
To determine the fraction of air molecules that must be pushed outside as the furnace raises the temperature from 16°C to 20°C, the ideal gas law (PV = NkT) is applied. The key is to convert temperatures to Kelvin for accurate calculations, as absolute temperature is essential in gas law equations. The ratio of the number of molecules before and after heating can be expressed as N2/N1 = T2/T1. The calculation shows that N2 equals approximately 0.80N1, indicating that about 20% of the air must be expelled. The provided answer of 0.0136 seems inconsistent with the calculations based on the temperature change.
pyizzle
Messages
1
Reaction score
0
HW Help: Absolute temp and ideal gas law

Homework Statement


What fraction of the air molecules in a house must be pushed outside while the furnace raises the inside temperature from 16C to 20C? The pressure does not change since the house is not 100% airtight.


Homework Equations


PV=NkT
PV/T=PV/T
?


The Attempt at a Solution


NkT=NkT? N2/N1 = T2/T1. N2 = .80N1. Answer provided is .0136. I can't figure how that answer comes about. Help would be grateful. Thanks.
 
Last edited:
Physics news on Phys.org
You need to take the temperature ratio in degrees Kelvin i.e. T=0 should be absolute zero.
 
Assuming the pressure inside the house does not change, your formula is correct. It's OK to solve in degrees C, the answer is relational.
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »
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 'Trying to understand the logic behind adding vectors with an angle between them'

Thread 'Trying to understand the logic behind adding vectors with an angle between them'

My initial calculation was to subtract V1 from V2 to show that from the perspective of the second aircraft the first one is -300km/h. So i checked with ChatGPT and it said I cant just subtract them because I have an angle between them. So I dont understand the reasoning of it. Like why should a velocity be dependent on an angle? I was thinking about how it would look like if the planes where parallel to each other, and then how it look like if one is turning away and I dont see it. Since...
View full post »

Similar threads

Why is temperature constant after gas has expanded?
Replies
33
Views
2K
What is the change in internal energy after two processes?
Replies
10
Views
2K
Why must we use absolute temperature for the Ideal Gas Law?
Replies
10
Views
3K
Gas temperature in a constant volume
Replies
8
Views
2K
Mixing two ideal gases with different V, T at constant pressure
Replies
16
Views
4K
Ideal Gas Law and Pressure at 80°C
Replies
2
Views
3K
How Does the Ideal Gas Law Apply in Multi-Part Physics Problems?
Replies
14
Views
2K
What would be a real-life example of the ideal gas law?
Replies
3
Views
10K
Thermodynamics: Ideal Gas Law, find the temperature
Replies
5
Views
3K
Thermodynamics - PV Diagram of an Ideal Gas
Replies
3
Views
3K

Hot Threads

Recent Insights

Back
Top