Question

Water flows through a horizontal pipe of varying cross-section. If the pressure is 1 cm of mercury when the velocity is 0.35 m/s. Find the pressure at a point where velocity is 0.65 m/s.

Answer 1

At 1^st point, P₁ = 1 cm of mercury

= 0.01m of Hg.

= 0.01 × (13.6 × 10³) × 9.8 P a;

v₁ = 0.35 m/s

At the second nd point,

p₂ = ?

v₂= 0.65 m/s and

ρ = 10³ hg/m³.

According to Bernoulli’s theorem,

= 0.01 × 13.6 × 10³ × 9.8 – 1/2 × 10³ × [(0.65)² – (0.35)²]

= 1182.8 Pa ⇒

= 0.00887 m of Hg.