How Do You Calculate Work Done by Gas in Thermodynamics?

  • Thread starter Thread starter Enoch
  • Start date Start date
  • Tags Tags
    Thermodynamics
AI Thread Summary
To calculate the work done by gas during expansion at constant pressure, the formula W = P(Vf - Vi) is used. The pressure of 95 atmospheres was correctly converted to Pascals, resulting in 9,623,500 Pa. However, the volume conversion was incorrect; 5 L and 10 L should be converted to cubic meters as 0.005 m^3 and 0.010 m^3, respectively. The correct calculation of work done would yield a different result than the initially calculated 4,811,750 Joules. Accurate unit conversion is crucial for obtaining the correct answer in thermodynamics problems.
Enoch
Messages
20
Reaction score
0
Thermodynamics problem: help needed!

Gas in a container expands at a constant pressure of 95 atmospheres. Find the work done by the gas if the initial volume is 5 L and the final volume is 10 L. Answer in units of Joules.

I thought this problem was straight-forward, but I missed it.

I converted 95 atmospheres into Pascals.

95 X 1.013e5 PA = 9623500

I then converted L into meters ^3.

Vi = 0.5 m^3
Vf = 1 m^3

With the units converted, I used the equation W = P(Vf - Vi) and got the answer 4811750 Joules. The answer is incorrect, or so I believe.

Where did I go wrong?
 
Physics news on Phys.org
Enoch said:
Gas in a container expands at a constant pressure of 95 atmospheres. Find the work done by the gas if the initial volume is 5 L and the final volume is 10 L. Answer in units of Joules.

I thought this problem was straight-forward, but I missed it.

I converted 95 atmospheres into Pascals.

95 X 1.013e5 PA = 9623500

I then converted L into meters ^3.

Vi = 0.5 m^3
Vf = 1 m^3

With the units converted, I used the equation W = P(Vf - Vi) and got the answer 4811750 Joules. The answer is incorrect, or so I believe.

Where did I go wrong?

There's no problem with the conversion of the pressure's units to SI,but remember that
1m^3=1000L
 
dextercioby said:
There's no problem with the conversion of the pressure's units to SI,but remember that
1m^3=1000L

Thanks alot!
 
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...
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...
Back
Top