Gon a standard 8×8 chessboard (alternating black and white squares), label the rows and columns . you pick a square at random. are these events independent. (a) a = {white square}; b = {black square}. (b) a = {even row}; b = {even column}. (c) a = {white square}; b = {even column}.

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)