Liquid ammonia at −20°c is flowing through a 18-m-long section of a 5-mm-diameter copper tube at a rate of 0.09 kg/s. determine the pressure drop, the head loss, and the pumping power required to overcome the frictional losses in the tube. the density and dynamic viscosity of liquid ammonia at –20°c are ρ = 665.1 kg/m3 and μ = 2.361 × 10-4 kg/m·s. the roughness of copper tubing is 1.5 × 10-6 m. the pressure drop is kpa. the head loss is m. the pumping power required to overcome the frictional losses is kw.