Topic 3) Efficiency & Energy Resources Flashcards
(20 cards)
what happens to wasteful energy?
it is dissipated into the system it was created in
what is the useful energy from an electric kettle?
the energy that heats the water
what is the wasteful energy from a electric kettle?
internal (thermal) energy heating the kettle.
infrared radiation transferred into the surroundings
what is the useful energy from a light bulb?
light radiation given out by the hot filament
what is the wasteful energy from a light bulb?
infrared radiation transferred to the surroundings
what is a way of reducing energy waste?
lubrication being used to reduce the friction between the parts of the machine
what is the equation of efficienc?
efficiency = (useful energy out) / (total energy in)
reasons devices waste energy
friction between parts
electrical resistance
unwanted sound energy
types of energy
fossil fuels
nuclear fuels
biofuel
wind
hydroelectricity
geothermal
sun
water waves
what type of energy store are fossil fuels?
chemical
what type of energy stores are nuclear fuels?
nuclear
what type of energy store is biofuel?
chemical
what type of energy store is wind?
kinetic
what type of energy store is hydroelectricity?
gravitational potential
what type of energy store is geothermal?
internal (thermal)
what type of energy store is tidal?
kinetic
what type of energy store are water waves?
kinetic
why are fossil fuels and nuclear energy reliable?
they operate almost continuously
comes on very quickly
starts generating electricity almost immediately
why is water power (tidal and hydroelectricity) reliable?
the moon causes the tides and rainfall filling reservoirs
why are wind and solar energy unreliable?
they cannot respond to increases demand, sunny and windy weather be guaranteed
