Heat and Temperature

Objectives Heat Temperature Absolute Zero Fahrenheit, Celsius and Kelvin Scales Methods of Energy Transfer Conductors and Insulators Specific Heat Heating Systems Cooling Systems

Heat The transfer of energy from the particles of one object to those of another object due to a temperature difference between the two objects

Temperature A measure of the average kinetic energy of all the particles within an object

Are heat and temperature the same thing?

Thermometer A device that measures temperature Liquid thermometers –Mercury –Alcohol

Fahrenheit Scale Based on the numbers 12 and 8 32°F = water freezes 212 °F = water boils Most familiar scale in the United States Daniel Gabriel Fahrenheit ( ) German Physicist

Celsius Scale Based on the number ten 0 °C = water freezes 100 °C = water boils Used in many foreign countries and by most scientists Anders Celsius ( ) Swedish Astronomer

Kelvin Scale Based on the metric scale and the number ten Developed to eliminate negative temperatures Used by many scientists, especially if they work with extremely low temperatures 0 K = -273 °C 273 K = water freezes 373 K = water boils NO degree sign!

Absolute Zero The temperature at which an object’s energy is minimal °C 0 Kelvin …and we think the Artic Circle is cold!!! But Mom, why can’t I wear shorts today? It’s supposed to be 254 Kelvin!

Convert °C to °F Fahrenheit temperature = (9/5 x Celsius temperature) T F = 9/5t Example: Convert 20 °C to degrees Fahrenheit

Convert °F to °C Celsius Temperature = 5/9(Fahrenheit temperature – 32.0) t = 5/9(T F – 32.0) Example: Convert 212 °F to degrees Celsius

Convert °C to Kelvin Kelvin temperature = Celsius temperature T = t Example: Convert 10 °C to Kelvin

Assignment Page 328 Practice Problems –Write the questions –Show your work!

Energy Transfer Conduction Convection Convection Current Radiation Conductor Insulator

Conduction The transfer of energy as heat between particles as they collide within a substance or between two objects in contact. –Objects must have direct contact

Convection The transfer of energy by the movement of fluids with different temperatures.

Convection Current The flow of a fluid due to heated expansion followed by cooling and contraction.

Convection Currents Vital to the earth –Weather –Ocean currents –Magma currents –Tectonic Plate movement

Radiation The transfer of energy by electromagnetic waves.

Conductor A material through which energy can be easily transferred as heat.

Insulator A material that is a poor energy conductor.

Using Heat Heating systems Cooling systems Refrigerant

Heating System Any device or process that transfers energy to a substance to raise the temperature of the substance.

Cooling System A device that transfers energy as heat out of an object to lower its temperature.

Refrigerant A substance used in cooling systems that transfers large amounts of energy as it changes state.

Review Conduction Convection Convection current Radiation Conductor Insulator Heating System Cooling System