Answer: Faster (by continuity equation).
- A Faster (by continuity equation)
- B Slower
- C At the same speed
- D Depends on fluid density
Correct answer: A. Faster (by continuity equation)
Explanation: A1 v1 = A2 v2. Smaller cross-section A2 requires larger velocity v2 for the same volume flow rate. This is seen in nozzles and hoses.
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.