Reviewing Thermal Phenomena

Powerful Ideas:

• Materials can feel hot or cold but be at the same temperature, room temperature, if have been in the same room for a long time without a heat source or sink
• Heat and temperature are different ideas

• Materials conduct heat energy at different rates

• Conductors: materials with high thermal conductivity (metals)

• Insulators: materials with low thermal conductivity (Styrofoam, plastic)

• Property of thermal conductivity is NOT related to property of density

• Heat flows from hot to cold materials

• If mix equal amounts of hot and cold water, equilibrium temperature is half way between initial hot and initial cold temperatures

• If mix unequal amounts of hot and cold water, equilibrium temperature will be closer to the initial temperature of the larger amount of water.
• Conservation of energy: heat lost = heat gained

• Heat lost by hot water = heat gained by cold water (and the environment)

• Amount of heat lost or gained depends on how much stuff you have (mass), what kind of stuff it is (c, specific heat), how much the temperature changed ( ∆t): (mc ∆t). If Heat lost by hot water = heat gained by cold water