5.7 Consider the steady and two-dimensional laminar boundary-layer flow of a constant-property fluid over a flat plate with a constant and uniform free-stream velocity U.. and temperature T.. The plate is maintained isothermal at Tw. Assume that the velocity and temperature profiles in the respective boundary layers at any x from the leading edge of the plate can be approximated as a function of the distance y normal to the plate by the relations: u U.. = 8 = and T - Tw To - Tw = y ST where 8 and &r are the velocity and thermal boundary layer thicknesses, respectively. a. Develop an expression for 8. b. It is estimated that 8/8 10. Develop an expression for the local Nusselt number Nux. c. Estimate the Prandtl number of the fluid.