Mechanical Properties of Fluids NCERT Solutions Class 11 Physics - Solved Exercise Question 10.24

Question 10.24:

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].

Solution:

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
∴ h = P / ρg
= 2000 / (1.06 X 10³ X 9.8)
= 0.1925 m
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.