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].

From the table 10.1,

Density of the blood, ρ = 1.06 × 10³ kg/m³

Gauge pressure, P = 2000 pa

We have,

Pressure, P = ρgh

Where,

ρ = density

g = acceleration due to gravity

h = height of the column

It is clear that, pressure exerted by the column of the blood should at least equal to inside vein pressure to enter blood into the vein from bottle.

Thus,

Required height,

=

= 0.1925 m

So, h≈0.2m required to make blood enter into the vein.