An M-rated self-priming centrifugal pump will be used to dewater an excavation during construction. The required pumping volume is estimated at 250 gal/min. The pump will be located 10 ft above the bottom of the excavation. The suction line will consist of 20 ft of 3-in hose, and the discharge line will consist of 80 ft of 3-in hose. Water will be discharged 30 ft above pump level. What is the total head developed?

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?