A closed, 0.4-m-diameter cylindrical tank is completely lled with oil (SG 0.9)and rotates about its vertical longitudinal axis with an angular velocity of 40 rad/s. Determine the di erence in pressure just under the vessel cover between a point on the circumference and a point on the axis.

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)