Physics · Chapter 09
🔥 Heat & Temperature
Conduction, convection, radiation.
💡 Heat is Energy in Motion
Heat always flows from hot to cold — never the other way. Temperature measures how hot something is (in °C, °F, or Kelvin).
Heat transfers in three ways:
• Conduction — through solids. A metal spoon in hot tea gets hot.
• Convection — through liquids/gases. Hot air rises, cold air sinks.
• Radiation — through empty space. The sun warms Earth this way. ☀️
Different materials heat up at different rates. This is called specific heat — water needs a lot of heat to warm up, which is why it's used in radiators.
Clinical thermometer — measuring body temperatureWikimedia Commons / CC BY-SA 3.0
Greenhouse effect — heat trapped by CO₂ and water vaporWikimedia Commons / CC BY-SA 3.0
🎬
Heat in Action
AnimationWater heating up. Bubbles rise (convection), thermometer climbs. Slide the heat below.
🧪
Crank the Heat
ExperimentTurn the flame up. Watch the temperature rise and bubbles appear when it boils.
50%
Water stateWarming
Water boils at 100°C. Below that, just hot. Below 0°C, it would freeze.