The "solar constant" s0 ≈ 1.36 kw/m2 (the mean solar radiation intensity felt on earth orbit) is calculated using the mean earth-sun distance. in practice, the actual earth-sun distance deviates from its mean by about ±2%, depending on the time of the year. how much variation would you expect for the actual solar intensity over the course of a year? (15 points)

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)