To appreciate how viscous drag are being computed if we have thevelocity field, let us consider the following velocity field for aflow of Newtonian viscous fluid u = x + 2y v = x 2 + y w = 0(4.158) The fluid has viscosity of 10?2 kgm?1 s ?1 (a) Determinethe viscous stresses on the reference fluid element.(b) Determinethe viscous stress vector acting on a surface aligned at an angleof 45 degrees (counterclockwise) from the x?axis.(c) Determine theviscous force acting on the same surface if surface spans from x =2 to x = 5 and its length in the z-direction being 2 m.
