Why do boats float but coins sink?
Show answer & explanation
Answer: Shape determines buoyancy
Water pushes boats up more — Wrong. Water does push up (buoyancy), but the amount depends on volume displaced—shape matters more than object mass.
Shape determines buoyancy ✓ — Correct! Archimedes' Principle: buoyant force equals weight of displaced water. Boat's hull shape displaces large water volume (heavy), creating upward force exceeding boat's weight—floats! Coin is dense—small volume displaces little water, insufficient buoyancy—sinks. Steel ships float because hull spreads mass over huge volume. Crush aluminum can—it sinks (same mass, less displaced water). Shape, not just density!
Coins are too small to float — Wrong. Size doesn't determine floating—leaves float, boulders sink. Buoyancy depends on displaced water volume versus object weight (shape matters).
More Physics in Daily Life questions
- In a warm office that already reads 26 C, which change can make people feel cooler without lowering the thermostat?
- Why might 26 C feel acceptable in a breezy naturally ventilated summer building but too warm in a sealed winter office?
- On a warm humid day, why can the same 27 C room feel much worse once you start sweating?
- Why can moving air make a 27 C room feel cooler without changing the thermometer?
- Which hidden factor can make a desk beside a cold window feel chilly even when the thermostat across the room still reads 22 C?
- In the same 22 C room, why might someone who just climbed stairs feel warm while someone sitting in a T-shirt feels chilly?