Answer: The hollow sphere has lower average density than water while solid sphere has higher density.
- A The hollow sphere has lower average density than water while solid sphere has higher density
- B The hollow sphere is generally lighter in absolute weight than the solid one in many documented cases
- C Water seeps into the hollow sphere's interior cavity through tiny pores according to conventional understanding
- D The hollow sphere has a larger exposed surface area than the solid one in routine practice
Correct answer: A. The hollow sphere has lower average density than water while solid sphere has higher density
Explanation: Floating depends on average density. Hollow sphere: total mass / total volume < ρ_water. Solid sphere: density of material > ρ_water. Ships float because their average density (steel hull + hollow interior with air) is less than 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.