Fire services arrived at a site to put out a fire on the ground floor of a building. the fire chief decided there is no need to turn on the pump in the fire truck since fire is on lower grounds and nozzle connection at the end of the hose can be used. the diagram below shows the arrangement of the firefighting efforts through a hose-pipe connected to the tank in the truck. the following parameters are known:
ρ=1000 kg/m^3 (water)
d_1=35 mm
d_2=d_3=110 mm
u_2=3.7 m/s
p_2=200 kpa (gauge)
p_1=atmospheric
z_2=z_1=0.9 m
q=0.035 m^3/s
α=1 (assuming fully developed turbulent flow)
calculate the velocity at the nozzle exit (u_1).
calculate the pressure at the lowest point in the hose-pipe (p_3).
determine the height of water (h) in the tank that provides the pressure (p_3) at location 3. was the pump required?
if flow was reversed through the nozzle, find p_2 that will result in an inward velocity of u_2=1.8 m/s at location 2.