What's the Volume Ratio After Halving the Pressure on an Ideal Gas?

[sk8in43va]

Homework Statement

1)The pressure on an ideal gas is cut in half,
resulting in a decrease in temperature to
0.604038 of the original value and a change
in the volume.
Calculate the ratio of the final volume to
the original volume of the gas.

2) Steam moves into the cylinder of a steam
engine at a constant pressure of 2.6 × 105 Pa.
The diameter of the piston is 25.6 cm, and the
piston travels 31.3 cm in one stroke.
How much work is done during one stroke?
Answer in units of J

3)A steam engine has a boiler that operates at
295◦F , with a temperature of 180◦F.
Find the maximum efficiency of this engine

Homework Equations

1) This problem I am not sure

2)Same thing. I have 40 problems and I am posting the few I don't get. maybe (Qin = Wout + Delta U)

The Attempt at a Solution

1) No idea how to attempt.

2)No idea. 3)
295F = 146.11 C + 273= 419.11
180 F = 82.22 C + 273= 355.22

355.22/419.11 = .84755
(1 - .84755) = .1524 = 15.24%

 

[Abhilash H N]

For the first one, since the process is not specified, try using Ideal gas equation.
For the second, since the process is isobaric use the formula of work done during the process.
The attempt for the third question is correct.

 

[SteamKing]

You should recognize that degrees Rankine is the absolute temperature scale using Fahrenheit degrees:

deg. R = deg. F + 459.67