Investors group constructed a lamp factory its construction cost (20 ) million $. It is explained that selling price for a thousand lamp is (2500) $ by studying found that production cost of a thousand lamp reaches (1000) $ 1- Find the production quantity that specifying break -even - point.
2- Find the number of years must be gone to return the capital if the maximum power for the factory was 4000 a lamp per day.

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)