Question
Find the internal energy of air in a room of size 3m x 4m x 6m at pressure 75cm of mercury.
Solution
The internal energy of V volume of gas at pressure P is given by,
... (1)
we have,
Volume of the room, V=3m x 4m x 6m = 72m3
Pressure, P=75cm of mercury
=75 x 13.6 x 980 dyne/cm2
= 9.996 x 104 N/m2
Air is mixture of diatomic gases.
Therefore,
y = 1.4
Putting values in equation (1), we have
So, internal energy is given by,
... (1)we have,
Volume of the room, V=3m x 4m x 6m = 72m3
Pressure, P=75cm of mercury
=75 x 13.6 x 980 dyne/cm2
= 9.996 x 104 N/m2
Air is mixture of diatomic gases.
Therefore,
y = 1.4
Putting values in equation (1), we have
So, internal energy is given by,
