Question

Arteriosclerotic plaque narrows down a section of an artery
to 20% of its normal cross-sectional area. What is the
pressure in that section if immediately before it the pressure
is 100 mmHg and the flow speed is 0.12 m/s?

Answer 1

Equation of continuity:

$$A_1v_1=A_2v_2$$

$$A_1v_1=0.2A_1v_2$$

The flow speed in this section:

$$v_2=5v_1=5(0.12)=0.6\frac{m}{s}$$

Bernoulli’s Equation:

$$p_1+0.5\rho v_1^2=p_2+0.5\rho v_2^2$$

$$13332+0.5(1050)(0.12)^2=p_2+0.5(1050)(0.6)^2$$

$$p_2=13151\ Pa$$