Answer: Density of material / density of water.
- A Density of material / density of water
- B Density of water / density of material
- C Mass of material / mass of water
- D Volume of material / volume of water
Correct answer: A. Density of material / density of water
Explanation: Relative density = density of substance / density of water at 4°C (approximately 1000 kg/m³). It is dimensionless. A relative density greater than 1 means the material sinks in water.
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.