Why do ice skates glide smoothly?
Show answer & explanation
Answer: Pressure melts thin water layer
Blade sharpness cuts through — Wrong. Sharpness helps control, but gliding comes from pressure melting thin water layer under blade that acts as lubricant.
Pressure melts thin water layer ✓ — Correct! Blade's narrow edge concentrates skater's weight—creates high pressure. Increased pressure lowers ice's melting point slightly (pressure melting). Thin water layer forms under blade—acts as lubricant reducing friction. Skate glides on water film! Water refreezes behind blade. Works best near 0°C—too cold (-30°C+) and pressure doesn't melt ice effectively. Same principle: snowball packing (hand pressure melts/refreezes)!
Cold reduces friction naturally — Wrong. Cold doesn't reduce friction—ice is actually more friction at very cold temperatures. Pressure melting creates lubricating water layer.
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?