Consider a tornado as air moving in a circular pattern in the horizontal plane. If the wind speed is 200 mph and the diameter of the tornado is 200 ft, determine the radial pressure gradient. If it is desired to model the tornado using water in a 6 in. diameter tube, what speed is needed to give the same radial pressure gradient?

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)