CGPET 2021 Solved Paper

Given, heart pumps blood in volume per minutes,
AV=5L∕min
AV=

5×10−3

60

m3∕s

Here as shown in figure, area of arteries is A and velocity of blood is v. Thus, the volume flows per second inside arteries is given by (A.v).
Height of mercury, column, hHg=150mm
=150×10−3m
Density of mercury, ρHg=13.6×103kg∕m3
and g=10m∕s2
Power (in watt) = ?
In this case, we find instantaneous power, P
=F.v .........(i)
Since, F=pressure×area
and pressure =hHg.ρHg.g
Put these values in eq. (i), we get
P=hHg.ρHg.g.(A.v) ........(ii)
=150×10−3×103×10×

5×10−3

60

=

(15)×(136)×(5)

6

×10−3
=1700×10−3=1.70W