2-1 The pump was used to transport 20C water from an open storage tank to a closed container with a gauge pressure of 210 Pa. The liquid levels of the two tanks were constant, and the relative positions of the parts were shown in the attached figure. The transporting pipe has a size of 108mmx4mm,is also made of seamless steel with a suction pipe length of 20m and a discharge pipe length of 100m (each pipe length includes the equivalent length of all local resistance). When the valve is fully open, the vacuum gauge reads 30000Pa, the vertical distance between the two pressure gauges is 0.5m, ignoring the resistance between the two pressure gauges, the friction coefficient is 0.02. Try to answer these questions: (1) What is the flow rate of the pipe when the valve is fully open, m.h? (2) What is the pressure at the outlet of the pump, Pa? (3) What is pump head, m? 10m Figure of exercise 2-1 O (4) If the centrifugal pump is found to have an air-binding phenomenon after one year of operation, try to analyze the cause. storage tank to somewhere. The pump is