## Thursday, June 10, 2010

### Ejs Open Source Ideal Gas Model based on Kinetic Theory of Gas « on: March 13, 2010, 09:02:30 AM »

 http://weelookang.blogspot.sg/2010/06/ejs-open-source-ideal-gas-model-based.html Ejs Open Source Ideal Gas Model based on Kinetic Theory of Gas https://dl.dropbox.com/u/44365627/lookangEJSworkspace/export/ejs_users_sgeducation_lookang_gas2DPVnRTwee11brownianFKH.jar author: fu-kwun hwang and lookang
Ejs Open Source Ideal Gas Model based on Kinetic Theory of Gas
« on: March 13, 2010, 09:02:30 AM »

Particle model of ideal gas
This java simulation use 10 to 200 particles to simulate the particle of ideal gas. Each particle has the same speed moving in random direction. Piston will move down due to the gravity and move up because collision from particles.
You can change the velocity and pressure with the slider bar
Explain why the volume in the simulation is changing all the time.
Answer: the random collisions of the particles with the wall causes a fluctuation in the (N*m(delta v) /dt) rate of Change of momentum with the walls and since P = F/A = N*m(delta v) /dt*A

New Model customized by lookang for the following:
Assumptions of ideal gas

1. The molecules in the gas can be considered small hard spheres. ( un-checkbox magnify for "small" & "hard sphere" is in the motion because the molecules do not deform or change the spherical shape)
2. All collisions between gas molecules are elastic and all motion is frictionless (no energy is lost in collisions or in motion). ( vary the coefficient of restitution to observe what if the collision are not perfectly elastic )
3. Newton’s laws apply. ( in the absence of external force, the particles continue in the state of motion, constant velocity)
4. The distance between molecules on average is much larger than the size of the molecules. ( un-checkbox magnify for "small", can you observe the molecules move a large distance before hitting another particle? )
5. The gas molecules are constantly moving in random directions with a distribution of speeds. (observe the histogram, do you see a distribution of speed in the molecules, even though the particles are started with the same speed?)
6. There are no attractive or repulsive forces between the molecules or the surroundings. ( the particles do not experience forces between particles except when the particles collide in a very short duration, external walls do not affect the motion of the molecules except during the very time of collision with walls, that the perpendicular component of velocity re-bounce.)

Additional option in applet to change elastic to inelastic (i.e. coefficient of restitution), p-V, p-T and V-T graphs

Original Source: This java applet was created by Fu-Kwun Hwang with Easy Java Simulation (Ejs) from Francisco
the original applet is from http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=632.0 New Model customized by lookang in Ejs Open Source Ideal Gas Model based on Kinetic Theory of Gas