1. The problem statement, all variables and given/known data Here's the velocity profile of the water across the depth . I dont understand why The max velocity occur at the top surface 2. Relevant equations 3. The attempt at a solution Is it because the friction on the top surface of water only comes from the below , whereas for the water below the top surafce , it has higher friction from the moving on the top , and moving water beneath it .... Is my concept correct ?