Chapter 10 Heat and Temperature

Temperature Page 324 Temperature is proportional to the average kinetic energy of an object

Measuring Temp Thermometers –Page 325 Based on the principle that most objects expand when their temperature increases

Measuring Temp Common Scales –Celsius –Fahrenheit –Kelvin – absolute zero

Energy Transfer Always from higher temp to lower temp Heat – page 330

Dr. Carlson Dr. Carlson Thermodynamics Dr. Carlson

Methods of Energy Transfer 3 ways –Conduction –Convection –Radiation

Conduction Page 332 Involves objects in direct contact Example: metal fork that holds marshmallow

Convection Page 332 Movement of warm fluids – liquid or gas Convection Current Example: warm air around the campfire

Radiation Page 333 Does not require physical contact between objects Example: heat you feel when you stand near the campfire

Conductor Page 334 What makes a good conductor? Metals better than non- metals

Insulators Page 335 Slow transfer of energy as heat Example: –wooden spoon

Specific Heat Page 336 Characteristic physical property Ratio can be used to predict larger changes for masses other than 1 kg

Using Heat Machines can transfer energy as heat from one place to another Examples? –Air Con, Fridge,

Using Heat Conservation of Energy Energy moves from high temp to lower temp

Air Conditioner Removes energy as heat from the warm air Transfers energy to air outside the room

Cooling System Page 343 Often use evaporation and condensation Refrigerant – page 344

Cooling System Liquid – Gas - Liquid Changes of state always transfer lots of energy

Heating Systems Page 340 Transfers heat from outside to inside Need a source of energy

Heating Systems Furnace or solar energy can be used to heat air or water solar Which can be pumped through a building to transfer energy and increase temperature

Usable Energy Some is lost through conduction and radiation Usable energy decreases Insulation can decrease loss