You plan to install an active, liquid-based solar heating system for hot water. There are four candidate collector systems. Your calculations provided the following data for the month of June. Using f-charts/equations, which of the four collector systems will provide the most collected energy for the month? X Y2.87 0.963.466 0.9983.229 1.085.525 1.0094

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)