perfectly elastic collision vs elastic collision?

[Saturation]

Is there a difference between them? I think that a perfectly elastic collision is one in which the 2 particles collides, and move away or in the same direction, WITHOUT sticking together, while an elastic collision can be one in which the particles stick together.

My book says that the "relative speed of approach = relative speed of separation" rule, only applies for perfectly elastic collisions, which is where I thought that it must be one in which the particles don't stick, since if they did stick, there would be no separation!

Pls confirm this!
thanks!

 

[workinghard]

wat i think is dat in non elastic collisons particles stick 2gthr but this doesnot happen in most cases... dre r collisions where da relative speed of appraoch is relative speed of seperation n ke b4 collision is ke after collision....
in normall elastic collisons doh de particles are seperated after collisons da speeds differ n so does KE ... 2 chk for ans u calc KE n this ll tell u whether its perfectly elastic or not
doh some times simple elastic collisions r considered as non elastic... did this ans u???

 

[intel1993]

hey our sir told that in the case of sticking of masses most of the collisions are elastic but if the the difference between the two of the masses is large than it will turn into an inelastic collision,....................................