First of all thank you for the quick reply, but, sorry, I'm not a native speaker and when you start talking about flowers and the like as well as the slope comparison, I don'T have a clue what you are trying to say...
Thanks a lot :) but unfortunately once again doesn't explain why one multiplies with tau, and therefore uses the maximun/final velocity of the elctron before each collision instead of its average velocity.
Why is the drift velocity of an electron in a wire defined as: tau*(E*e/m) and not 1/2 *tau* (eE/m) as it is the AVERAGE VELOCITY!? because the above defintion of drift velocity is the velocity that is attained before the collision so rather the maximum velocity of the elctron, isn't it?