Answer: 14.3 cm.
- A 14.3 cm
- B 1.43 cm
- C 143 cm
- D 0.143 cm
Correct answer: A. 14.3 cm
Explanation: h = 2T cosθ/(ρgr) = 2 × 0.07 × 1/(1000 × 10 × 0.1×10⁻³) = 0.14/(1) = 0.14 m = 14 cm ≈ 14.3 cm.
Since the same volume of fluid must pass every cross-section per second (continuity), the fluid speeds up where the pipe narrows; Bernoulli's equation then says this faster-moving fluid has lower pressure - the principle behind a venturi meter and an aircraft wing's lift.
Concept context
Pressure, buoyancy, Bernoulli equation, viscosity, and surface tension.