Energy Resources and Energy Transfers Flashcards
State the nine types of energy
electrical light sound kinetic nuclear thermal/heat gravitational potential elastic potential chemical
State the principle of the conservation of energy
energy can never be created nor destroyed, its only ever transferred from one form to another
When is energy only useful ?
when it can be transferred from one form to another
efficiency =
useful energy output / total energy input
State the meaning of dissipate
spread out and lost
Can a device be 100% efficient?
no, wasted energy is always dissipated as heat
from the entire energy output into a machine, how much usually becomes heat?
by the end, all of it, both useful and wasted, as it gets transferred to cooler surroundings it dissipates though
what is the measurement of all energy ?
Jules J
Electrical devices convert electrical energy into…
sound light (and wasted heat)
Batteries convert chemical energy into…
electrical to run electric devices (and wasted heat)
Gravitational and elastic potential energy always convert into…
kinetic energy first (and wasted heat)
what is radiation?
transfer of heat by electromagnetic waves which occurs in solids, liquids and gases
what is conduction?
the process where vibrating particles pass on extra kinetic energy to neighbouring particles
what is convection?
process where more energetic particles move up (less dense) to cooler regions, bringing their heat with them
loft insulation
layer of fibreglass wool across loft floor and ceiling to reduce convection and conduction
hot water tank jacket
fibre glass wool covering tank to reduce convection and conduction
double glazing
two layers of glass with an air gap reduces conduction and convection
draught-proofing
strips of foam around doors / windows to reduce convection
cavity wall insulation
foam between bricks prevents convection
air in foam prevents conduction