Answer: 2 atm (1 atm atmospheric + 1 atm from water column).
- A 2 atm (1 atm atmospheric + 1 atm from water column)
- B 10 atm, mistakenly equating 10 m of depth to 10 atm directly
- C 1 atm, ignoring the added pressure of the overlying water column
- D 5 atm, from incorrectly halving the depth-to-pressure conversion
Correct answer: A. 2 atm (1 atm atmospheric + 1 atm from water column)
Explanation: P = P<sub>0</sub> + ρgh = 10⁵ + 1025 × 10 × 10 ≈ 10⁵ + 1.025×10⁵ ≈ 2.025 × 10⁵ Pa ≈ 2 atm.
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.