Question

During 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].

Answer 1

Gauge pressure, P = 2000 Pa

Density of whole blood, ρ = 1.06 × 103 kg m–3

Acceleration due to gravity, g = 9.8 m/s2

Height of the blood container = h

Pressure of the blood container, P = hρg

The blood may enter the vein if the blood container is kept at a height greater than 0.1925 m, i.e., about 0.2 m.