Forms of energy: thermal (heat), light, electrical, sound, kinetic, chemical, nuclear and potential (elastic and gravitational)
E.g candle and a box of matches: kinetic-light & heat
Energy is transferred from one form to another.
E.g Thermal energy always flows from a region of higher temperature to a region of lower temperature.
Efficiency= useful energy output/total energy input x 100
efficiency is calculated as a percentage (%) therefore u will have to times it by 100
Sankey diagrams shows what happens to the input energy and in what proportion it is transferred to various forms.
E.g This is the Sankey diagram for a typical filament lamp.
E.g candle and a box of matches: kinetic-light & heat
Energy is transferred from one form to another.
E.g Thermal energy always flows from a region of higher temperature to a region of lower temperature.
Efficiency= useful energy output/total energy input x 100
efficiency is calculated as a percentage (%) therefore u will have to times it by 100
Sankey diagrams shows what happens to the input energy and in what proportion it is transferred to various forms.
E.g This is the Sankey diagram for a typical filament lamp.
The efficiency of the filament lamp is (10 ÷ 100) × 100 = 10%.
This means that 10% of the electrical energy supplied is transferred as light energy (90% is transferred as heat energy).
Conduction= atoms vibrate and heat is transferred from one atom to another
Convection=when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy. Heat energy is transferred from hot places to cooler places by convection.
Radiation=It is the movement of heat in the form of infra-red waves.
This means that 10% of the electrical energy supplied is transferred as light energy (90% is transferred as heat energy).
Conduction= atoms vibrate and heat is transferred from one atom to another
Convection=when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy. Heat energy is transferred from hot places to cooler places by convection.
Radiation=It is the movement of heat in the form of infra-red waves.
Role of convection in everyday phenomena
InsulationFor the human body, we wear woolen clothes to keep ourselves warm, wool feels warm because it traps a lot of air.