Explaining ideal gas

behavior

Elastic and Inelastic collisions

Explaining ideal gas behavior• Kinetic Energy is the energy associated with the

motion of particles – molecules, atoms, and ions. Some molecules may posses more than the average kinetic energy; others may have less than the average kinetic energy. It is the average kinetic energy that is proportional to absolute temperature, the more kinetic energy the substance has and the more rapidly the particles move

Elastic and Inelastic

collisions

• A ball bouncing on the ground loses some kinetic energy on collision. The lost kinetic energy changes into heat as a result of friction.

• The ball thus gradually slows down until it comes to rest. Collisions with loss of Energy are term Inelastic.

Inelastic collision

• Perfectly elastic collisions are those in which no kinetic energy is lost in the collision. Macroscopic collisions are generally inelastic and do not conserve kinetic energy, though of course the total energy is conserved. The extreme inelastic collision is one in which the colliding objects stick together after the collision, and this case may be analyzed in general terms:

Inelastic collisions

Kinetic energy lost in

Inelastic collisions

Elastic collision• If collisions between gas particles involved

friction, the molecules would gradually slowdown and lose kinetic energy

• The gas pressure would slowly drop to zero. However, this is never observed of gases. We can thus, postulate that molecular collisions in gases are frictionless or perfectly elastic.