Fully developed flow in a pipe implies uniform velocity profile velocity profile does not change in the flow direction flow parameters do not change with time none of the above
Answers
The momentum of the flat plate is zero and the momentum of the uniform flow has a finite value. When the incoming uniform flow flows over a flat plate, the fluid particles near the plate will stick to the plate (no-slip condition). That means that the momentum of the flat plate is diffused to the fluid. The reason for this no-slip condition is adhesion between the flat plate and the fluid particles. The fluid particles have a force between them that holds them together, which is cohesion. When the fluid flows this cohesive force along with adhesion shows itself in the macroscopic scale as viscosity. As the flow proceeds downstream of the flat plate the viscosity is able to slow down more and more fluid layers above the flat plate. This is what is called momentum transfer. And hence the boundary layer thickness increases as the fluid moves downstream.