During a blood transfusion, the needle is inserted in a vein where the gauge pressure is 2000 Pa. At what height must the blood container be placed so that blood may just enter the vein? [Use the density of whole blood from Table 10.1]
Gauge pressure, P=2000Pa Density of whole blood, ρ = 1.06×103 kg/ m3 Acceleration due to gravity, g=9.8m/s2 Height of the blood container =h Pressure of the blood container, P=hρg h=P/ρg =2000/(1.06×103×9.8) =0.1925m The blood can enter the vein if the blood container is kept at a height higher than 0.1925 m, i.e., about 0.2 m
