4.Energy Flashcards
What is energy efficiency equal to?
Total useful energy output / total input
Describe process of conduction, convection, radiation
Conduction- energy from particles via conduct, only solid
Convection- particles w/ energy rise and space they leave fills with other particles, they then gain energy and rise etc. liquid and gas
Radiation- heat transferred as Infared rays
Why do metals have faster rate of heat transfer? (than non-metals)
Free electrons so more collisions transferring energy
How does insulation reduce energy transfers?
Insulators are bad at conducting heat, so if surrounding object they will prevent heat transferring
Eg. Air in double glazed windows
What is work done? Units?
What is power? Units?
Energy transferred, Joules
Rate of work done, Watts (J/s)
Describe energy transfers in generating electricity
Wind- kinetic to electric
Water-kinetic to electric
Geothermal- thermal heats water, water to steam, thermal of steam, kinetic to generator to electric
Solar heating- light to thermal
Solar cell- light to electric
Fossil fuels- chemical to heat, kinetic to electric
Nuclear power- kinetic, heat, kinetic, energy
