Using Heat Ch 13 Heat Sec 3 Page

First Law of Thermodynamics Energy that is transferred as a result of work, heat, or both is conserved This is also known as the Law of Conservation of Energy 87

Second Law of Thermodynamics Heat is always transferred from the warmer object to the colder one 87

Heating Systems Our body is a heating system –Some of the food we eat is transferred as heat to blood moving throughout the human body We are Endothermic organisms Normal body temp is 98.6° F (Or 37 ° C) 88

Solar Heating Used by reptiles and other ectotherms Ectotherms take on the temperature of their surrounding, use basking 88

Central Heating Furnace burns coal, fuel oil or natural gas Energy released is transferred to water, steam, or air Then, the steam, air or hot water is moved to each room through pipes 89

Active Solar Heating Solar heating systems use the same principle Solar panels collect sun's rays to heat water, The water moves through tubes in the house like the other water heating method This may require the use of electricity to move the water through the pipes 89

Passive Solar Heating Requires no external source to move the energy Depends upon radiation and convection currents in fluids Extra Credit possibility : Research a method of passive solar heating and make a presentation to the class

Cooling Systems Wall Units Central Air

Usable energy decreases in all energy transfers 90

Insulation Insulation reduces undesirable energy transfers R-value measures the ability to reduce unwanted energy transfers See chart on page439 –Which is the best insulator? –Worst? 90

Internal Combustion Engine Components of a typical, four stroke cycle piston enginefour stroke cycle (E) Exhaust camshaftcamshaft (I) Intake camshaft (S) Spark plugSpark plug (V) ValvesValves (P) PistonPiston (R) Connecting rodConnecting rod (C) CrankshaftCrankshaft (W) Water jacket for coolant flow 91

Four-Stroke Cycle Intake Compression Power Exhaust