## water-air composite pressure system

Hi all,
This is my first post since I'm unable to find the answer myself & on the net too.
My query is lets consider we have 3 types of system

1. Air tank at 10 bar pressure.
It will have105*10*1= 1000 KJ energy.

2. Water tank of volume 1 cum and height of 1 m.
It will have 5.04*h2 = 5.04 KJ (h= water head pressure)

3. Now lets say we have 2 cum of volume containing water of 1 cum and 1 cum air at 10 bar.
can I say we have energy in water= 5.01*1002 = 50400 KJ (10 bar=100 m of water)
plus when water is out of tank volume of air will be 2 cum at 5 bar.
then energy stored in air (considering isothermal expansion)= 500 KJ
so total 50900 KJ.

Am I doing wrong some where/ everywhere then where is it wrong?
If not why there is so diffrence in energy?
 PhysOrg.com physics news on PhysOrg.com >> Study provides better understanding of water's freezing behavior at nanoscale>> Soft matter offers new ways to study how ordered materials arrange themselves>> Making quantum encryption practical
 calling all scholars
 Pls help. Don't any one here study hydraulics.