11.For a sphere of radius 15 cm moving with a uniform velocity of 2 m/sec through a liquid of specific gravity 0.9 and dynamic viscosity 0.8 poise, the Reynolds number will be

12.The shear stress distribution for a fluid flowing in between the parallel plates, both at rest, is

13.For hydro-dynamically smooth boundary, the friction coefficient for turbulent flow is

14.When an ideal fluid flows past a sphere,

15.The boundary layer thickness in turbulent flow varies as