Thermal energy

Temperature is a measure of…

• The total amount of energy in an object

• The total amount of thermal energy in an object

• How much heat something gives off

• How fast the molecules in an object are moving

Heat is…

• Energy given off or absorbed by an object

• A measure of the motion of the molecules in an object

• The total amount of molecular energy in an object

How do we measure temperature?

Think about using a thermometer

How does the thermometer know how hot the substance is?

• The molecules of the substance bump into the thermometer and transfer energy. How often and how hard they bump into the thermometer are directly related to their speed.

• Temperature turns out to be related to the average speed of the molecules in a substance.

• Temperature is not a measure of the total amount of energy in an object.

• Thermal Energy = internal energy = a measure of the total kinetic and potential energy in an object

Name Water Freezes Room Temperature

Water Boils Absolute Zero

Fahrenheit32 70 212 -459

Celsiusq 21 100 -273

Kelvin 273 274 273 0

Temperature Converter

• http://www.onlineconversion.com/temperature.htm

• Since there is a minimum kinetic energy for particles(0 J), there is a lowest possible temperature-absolute zero.

Temperature and heat

• When you add heat energy to an object its temperature may or may not increase.

• Since heat is energy it can be measured in joules.

• 1 calorie is the amount of heat needed to raise the temperature of water by one degree.

• The amount of heat energy required to raise the temperature of a substance by 1o C is called specific heat capacity or specific heat.

Calculating Heat energy

• H=mcΔt• Where• H = heat energy added or removed• .m=mass• C = specific heat• Δt = change in temperature

Ways of using heat

• Forced air system-

Force heat                                                                    

Two pipe system                     

Electric heat

Solar heating

• There is a passive solar heat-receive sunlight during day and are stored.

• Active solar heating-receives solar energy from panels on south side

Thermodynamics

• First law of thermodynamics-

• Second law of thermodynamics