Question

Water enters through one end of a horizontal pipe of non-uniform cross-section with a velocity of 0.4m/s and leaves the other end with a velocity 0.6 m/s. The pressure of water at the first end is 1500N/m². What is the pressure at the other end? (Density of water = 1.010³kg/m³)

• A. 1000N/m²
• B. 100N/m²
• C. 500 N/m²
• D. 1400 N/m²

Answer 1

Answer: (D)

1400 N/m²

Answer 2

According to Bernoulli's theorem

P₁ + $\frac { 1 } { 2 } \rho v _ { 1 } ^ { 2 }$ = P₂ +

Or, P₁ – P₂ =

Or, P₂ = P₁ − $\frac { 1 } { 2 } \rho \left( v _ { 2 } ^ { 2 } - v _ { 1 } ^ { 2 } \right)$

Given : P₁ = 1500n/m², v₁ = 0.4m/s, v₂ = 0.6 m/s, P₂ = ?

∴ P₂ = 1500 – $\frac { 1 } { 2 }$ 110³ [(0.6)² – (0.4)²]

Or, P₂ = 1500 – 100 = 1400 N/m²