8.39 Hydraulic mining is to be done using water from a lake located 300 m above the mine site. A 900 m long fire hose with an inside diameter of 75 mm and a relative roughness of 0.01 will be used. Couplings are located every 10 m along the hose. The nozzle outlet diameter is 25 mm and its loss coefficient is 0.04 based on the upstream velocity. Estimate the maximum outlet veloc- ity from the hose and the maximum force exerted on a rock face by the water jet.
