Question

Water is flowing through a pipe of non unifrom cross section. at the point when the velocity of flow is 35 cm/s, the pressure is 1 cm of mercury. What is the pressure at the point where the velocity of flow is 65 cm/s?(0.887 cm of mercury)

Answer 1

According to Bernoulli's eqn.

$P+pgh+\frac{1}{2}p{v}^2=constant$

$1g+0.5p{35}^2=1gh+{0.565}^2$

$gh=1\times 10\times 1+0.5\times 1\times {35}^2-0.5\times 1\times {65}^2$

$gh=1490cm$

$h=\frac{1490}{10}=149cm$