1. The problem statement, all variables and given/known data why the author use major loss due to fluid friction is fL(Q^2) / 3(d^5) ??? according to darcy weisbech , the major loss due to friction has the formula of fL(v^2) / 2gD why the author wrote it as fL(Q^2) / 3(d^5) ??? I dont understand 2. Relevant equations 3. The attempt at a solution since v= Q/ A , we can rewrite it as fL(Q^2) / 2g(π^2)(d^5) , am i right ?