Answer: 5 m/s.
- A 5 m/s
- B 2.5 m/s
- C 12.25 m/s
- D 1.25 m/s
Correct answer: A. 5 m/s
Explanation: Torricelli: v = √(2gh) = √(2 × 10 × 1.25) = √25 = 5 m/s.
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.