Engineering students are often asked to design a "concrete boat" as part of a design project to illustrate the buoyancy effects of water. as a proof of concept, determine the depth d at which the concrete box will rest in the fresh water. the box has a uniform wall thickness of 3 in. on all sides and the bottom.

Amixture of slurry and mud is to be pumped through a horizontal pipe of diameter 500 mm. the fluid behaves as a bingham plastic with a yield stress of 30 pa and viscosity 0.04 pa.s. describe the effects of the shear stress through a transverse section of the pipe by plotting the variation in shear stress and velocity profile: (i) just before the slurry starts to move (ii) as the slurry flows when the pressure gradient is double that in part (i)