Energy Conversions & ConservationForces, Motion, and Energy p. 132-141
Conversions• Changing one form of energy to another. – Kinetic Energy-Thermal, Electrical, Sound, Light – Potential Energy-Chemical, Nuclear • Elastic Potential Energy-Rubber bands; any object that will return to its original shape once it has undergone a potential kinetic conversion.
Some conversions of Electrical Energy Electrical Energy ConversionsHair Dryer Electrical Thermal SoundAlarm Clock Electrical Light SoundBattery Chemical ElectricalLight Bulb Electrical Light ThermalBlender Electrical Kinetic Sound
Types(s) of Energy:Heat (thermal) energy inflameLight energy in flameChemical energy in matchused to light it
What is the energy transformation? • A fire burning. ___________energy _________energy
What is the energy transformation? • An apple _________energy __________energy
What is the energy transformation? • Nuclear Power Plant __________energy ___________ energy __________ energy
What is the energy transformation? • Desk Lamp ____________ energy ______________ energy
What is the energy transformation?• Kerosene lantern___________ energy __________ energy ___________ energy
Machines-Mechanical Energy• There are simple • There are complex machines such as: machines such as: – Screws – Scissors-2 wedges and – Levers-Claw end of a a lever hammer, see saw – Wheelbarrows-lever – Wheel & axle-large and wheel & axle wheel secured to a smaller shaft Complex machines are – Pulley-flagpole formed from 2 or more – Inclined plane-ramp simple machines.
Conservation• Law of conservation of energy• Friction• http://youtu.be/GTVqtGTfIc8
Closed System• Energy is conserved within a closed system where a group of objects only transfers energy to each other.
Energy Efficiency• A comparison of the amount of energy before a conversion with the amount of energy after a conversion. – Remember, every time energy converts it loses friction.