alleryFor a steadily flowing incompressible fluid, the continuity equation A·v = constant means:
APressure stays constant
BEnergy is fully conserved
CSpeed is the same everywhere
DMass flow rate is the same
Answer & Solution
Correct answer: D. Mass flow rate is the same
1. For an incompressible fluid in steady flow, the volume flow rate A v through any cross-section is constant.
2. Mass flow rate ρ A v is also constant since ρ is constant.
3. So narrower pipes have faster flow — speed is NOT constant.
4. Pressure (Bernoulli) and energy follow from this, but the continuity equation per se states mass conservation.
_Source: syllabus Physics Ch 9 §9.5 Equation of Continuity_
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