Homework Help: Thermofluids question help

Thermofluids question HELP asap!!!

1. The problem statement, all variables and given/known data
I would like to know what forces acting and a transition from laminar to turbulent flow is faced. Also what factors affecting the transition?

3. The attempt at a solution

In my opinion the possible forces which acting on a pipe wall is the friction force. Also i think the factors which causing this, is the high velocity which means high Reynolds number and therefore turbulent flow but i don't believe that this is the explanation for this.

Any help????

Cheers !!

 

no one can help???

 

bump~?? no one?