What is Heat?Heat is the transfer of energybetween objects that are differenttemperatures.

What is Heat?Energy is alwaystransferred from the object with highertemperature to the object with the lowertemperature.

Heat is a Transfer of EnergyIf heat is a transfer of energy, what FORM of energy is being transferred?

Heat and Thermal EnergyThermal Energy is the totalenergy of the particles that make up the substance.

Heat and Thermal EnergyWhich has more thermal energy, a substance at a hightemperature or a substance at a low temperature? Discuss with your neighbor.– An object at a high

temperature. Why?

Heat and Thermal Energy

Thermal energy also depends on how much of a substance you have.

Heat and Thermal EnergyWhich has morethermal energy, an ice berg or a pot of boiling water?– An ice berg, but

why?

Reaching the Same TemperatureWhen objects at differenttemperatures come in contact, energy will always be transferred from the object with higher temperature to the object with the lower temperature until bothobjects reach the same temperature.

This is called reaching Thermal Equilibrium.

Example:Drinks in a

cooler

3 Types of Heat Transfer:

Conduction

Convection

Radiation

1. ConductionConduction is the transfer of thermal energy from one substance into another through direct contact.

1. ConductionExamples:

– A metal spoon in a bowl of hot soup.

– An iron rod in the fire place

ConductionSubstances that conduct thermal energy very well are called conductors.

Substances that do not conduct thermal energy very well are called insulators.

2. ConvectionConvection is the transfer of thermal energy by the movement through a liquid or gas.

2. ConvectionExamples:

– Pot of boilingwater

– Air currents

3. RadiationRadiation is the transfer of energy through matter or space as electromagnetic waves, such as visible light or infrared waves

3. RadiationExamples:– The sun

– Fire

What is Temperature?• Temperature is a measure of the average kinetic energy of the particles in an object.

Temperature ScalesFahrenheit °F

(Typically used by Americans)

Celsius °C(Used by the rest of the world)

Kelvin K(Used by scientists)

Fahrenheit Celsius Kelvin

Water Boils

212°F 100°C 373

Body Temp.

98.6°F 37°C 310

Room Temp.

68°F 20°C 293

Water Freezes

32°F 0°C 273

Absolute ZeroAt absolute zero, all moving matter should stop.

–273.15 °C - Celsius

–459.67 °F - Fahrenheit

Temperature Conversions

Fahrenheit to Celsius

°C = 5/9 x (°F – 32)

Celsius to Fahrenheit

°F = (9/5 x °C) + 32