Answer: Smaller bubble (r2) shrinks and larger (r1) grows.
- A Smaller bubble (r2) shrinks and larger (r1) grows
- B The larger bubble shrinks while the smaller one grows instead
- C Both bubbles settle to exactly the same final equilibrium radius
- D Neither bubble's size changes once they are connected by the tube
Correct answer: A. Smaller bubble (r2) shrinks and larger (r1) grows
Explanation: Excess pressure in a soap bubble = 4T/r. The smaller bubble (r2) has higher pressure than the larger one (r1). Air flows from smaller to larger. The smaller bubble shrinks.
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.