Heat ICP Chapter 11

Heat/Temp/Energy Heat – flow of thermal energy Heat flows from the warmer object (higher energy) to the cooler one (lower energy) Temperature – average kinetic energy per molecule from random motion Thermal Energy – energy of moving/vibrating molecules – energy related to temperature

Units Heat is energy – it can be measured in Joules (like KE, PE, and work), calories, or BTU (British Thermal Units). 1 calorie = 4.186 joules 1 BTU = 1055 joules

Conductors, Insulators Conductor – transfer or move heat energy Insulator – Keeps the heat energy inside – keeps it from leaving

Specific Heat The temperature increase of an object depends on its mass and the material from which it is made. Specific heat is a property of a material telling us how much heat energy is needed to raise the temperature of 1 kg by 1°C.

Specific Heat Knowing the Specific Heat (or Cp) value tells you how fast the temperature of something will change as it gains or loses energy. Metals will warm up (or cool down) fast Styrofoam will take a longer time and more energy to change temperature. Many mugs are made from ceramics. Will those have a larger or smaller specific heat than iron? Why do pots have plastic handles? Would you rather stir boiling water with a metal or a wood spoon?

Specific Heat Equation E = mCp(T2-T1) E  Heat Energy (J) M  mass (kg) Cp  Specific Heat (J/kgC) (T2-T1 )  change in temp (°C)

Heat Transfer Conduction Thermal Equilibrium

Heat Transfer Types Conduction Convection Thermal Radiation