HeatHeat

Not just hot or cold…Not just hot or cold…but much, much but much, much more!!!more!!!

What Is Heat? What Is Heat?

The transfer of The transfer of energyenergy between objects at between objects at different temperatures different temperatures

High Temperature High Temperature Objects Objects

Low Temperature Objects Low Temperature Objects

** Energy ** Energy moves from moves from high-temp. high-temp.

to low-tempto low-temp.

Heat and Thermal Heat and Thermal EnergyEnergy

Thermal Energy is the Thermal Energy is the energy that moves in energy that moves in heat transferheat transfer

Higher temp = higher Higher temp = higher thermal energy thermal energy

Lower temp = lower thermal energy Lower temp = lower thermal energy

What Changes Thermal What Changes Thermal Energy?Energy?

1. Temperature 1. Temperature

2. Amount of substance 2. Amount of substance More moving particles = more thermal More moving particles = more thermal

energy energy

Kinetic Energy of molecules!!Kinetic Energy of molecules!!

Thermal Energy is Thermal Energy is Related To…?Related To…?

Reaching The Same Reaching The Same TemperatureTemperature

The point at which The point at which both objects in both objects in contact reach the contact reach the same temperature…same temperature…

** ** NO CHANGENO CHANGE IN THERMAL IN THERMAL ENERGY OCCURS!!ENERGY OCCURS!!

Thermal Equilibrium Thermal Equilibrium

ConductionConduction

Transfer of thermal energy from one Transfer of thermal energy from one substance to another through direct contactsubstance to another through direct contact

Particles collide, causing the kinetic Particles collide, causing the kinetic energies of colliding particles to energies of colliding particles to INCREASEINCREASE!!!!!!

Particle speeds increase and decrease Particle speeds increase and decrease until they become equal giving us… until they become equal giving us…

The Same Temperature!!!!The Same Temperature!!!!

Conductors and Insulators Conductors and Insulators

ConductorsConductors – –

substances that substances that transfer transfer thermal thermal

energy well energy well

InsulatorsInsulators – –

substances that substances that do not transfer do not transfer thermal energy thermal energy

well well

ConvectionConvection

Transfer of thermal energy by the Transfer of thermal energy by the movement of a liquid or a gasmovement of a liquid or a gas

Causes higher-energy Causes higher-energy particles to separate and rise, particles to separate and rise, as they rise they cool, as they rise they cool, causing them to fall creating causing them to fall creating a…a…

RadiationRadiation

The transfer of energy through matter or The transfer of energy through matter or space as electromagnetic wavesspace as electromagnetic waves

Visible Light and Infrared Visible Light and Infrared WavesWaves