changes made:
1 added text to the code variable, to understand the meaning of the many variables
2 add the pPa = pBar*13600*(-g)*0.76; // when g is -9.8 to allow questioning of the relationship between Pa and Bar ( atm )
3 found a bug when N is change, the applet may hang, i used the _isPaused() to enable the slider N to prevent the hanging to occur.
4 add the V = volume*(0.00138)/0.00123; so that P.V= N.k.T is more close to the real life values of //1.01*e5*1.09*e-21 = 400*1.38*e-23*200 http://hyperphysics.phy-astr.gsu.edu/Hbase/kinetic/eqpar.html#c2
5 made the V slider respond better by  
[code]volume = V/(0.00138)*0.00123; // need for slider to understand what to do
_initialize(); // need for responsive[/code]
6 add color scheme
7 change drawing to new Ejs objects
8 fix a max limit problem for Volume by *2.2
9 changing all the suit real life data, using http://hyperphysics.phy-astr.gsu.edu/Hbase/kinetic/eqpar.html#c2 as the base calculator, amu = 18 water molecule
10 add collisions between molecules by adapting [img]http://www.compadre.org/profiles/hard_disk.jpg[/img]Ejs Hard Disk Gas Model written by Wolfgang Christian http://www.compadre.org/osp/items/detail.cfm?ID=7573
11 change N = 50 as the computation is too great to run at n =400 as explained by Hwang here about the about calculation on possible collision between any two particles.  A loop with 400*400 checking for collision.http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=632.msg5537#msg5537
12 remove 10 and 11 and deploy http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1484.0 Ejs Open Source Brownian Motion Gas Model Java Applet by Professor Francisco (Paco) Esquembre, Professor Fu-Kwun Hwang and lookang
13 added coefficient of elasticity between particles
14 added coefficient of elasticity between particles and wall
15 change the color of the gas to yellow
16 add Maxwell distributive speeds through Ejs Hard Sphere Gas Model written by Wolfgang Christian http://www.compadre.org/osp/items/detail.cfm?ID=7574 and http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1487.msg5608#new
17 added real calculation based on v[sub]rms[/sub]= Math.sqrt(speed[j]+......)/n;
18 added instantaneous Temperature calculation,
19 add total kinetic energy of N molecules = 1/2*m*v[sub]rms[/sub]*v[sub]rms[/sub]
20 add TKE = 3/2*N*k*T valid only for monoatomic particles, [b][color=red]did not account for diatomic TKE = 5/2*N*k*T , polyatomic TKE = 7/2*N*k*T[/color][/b]
21 new layout and hidden other panels
22 add mass but hidden to simply
23 hide TKE
24 adjusted k3m value from 50 to 2000 to prevent the volume from going to sub 10, thus avoiding the bug of particles "flying off"






challenges: Done!
add Maxwell distributive speeds
can learn from Ejs Hard Sphere Gas Model
written by Wolfgang Christian http://www.compadre.org/osp/items/detail.cfm?ID=7574
Ejs Hard Disk Gas Model
written by Wolfgang Christian http://www.compadre.org/osp/items/detail.cfm?ID=7573


removed, using the http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1484.0 Ejs Open Source Brownian Motion Gas Model Java Applet
[s]Done! 18 March
add collisions between molecules can learn from Ejs Hard Sphere Gas Model
written by Wolfgang Christian http://www.compadre.org/osp/items/detail.cfm?ID=7574
Ejs Hard Disk Gas Model
written by Wolfgang Christian http://www.compadre.org/osp/items/detail.cfm?ID=7573[/s]