Revered Members,
Mean free path is the average distance travelled by a molecule between two successive impacts. Let me get clarified whether i understood this concept from you. Please refer my attachment. So d(1) is the mean free path of the molecule(given in red). Am I right?

 

Mostly no. Try averaging all the distances. Further we do not usually consider the container, it is the distance between impacts between molecules.

This is an approximate concept molecules are not hard spheres, even the notion of impact is not well defined, how big an impact. Never the less if you understand its limitations it is useful for a large number of computations.

Your text should explain this more.