Energy Transfers Flashcards
How is energy lost in an electric heater?
Energy is lost to heat the copper that the tank is made from and to the atmosphere.
Where is energy lost in a car?
Energy is used to overcome the various friction forces that oppose motion. This can also cause energy to be transferred to heat.
Lost as sound (engine noise)
Lots of energy is converted to heat which is lost or heats the surroundings
What is the law for Conservation of energy?
Energy is not created or destroyed in any process. Only transferred from one form to another.
What is the equation for efficiency?
useful output/total input x 100%
Electrical energy
whenever a current flows
Light energy
from the sun, luminous objects, light bulbs
Sound energy
loudspeakers etc
Kinetic energy
anything that possesses motion
Nuclear energy
released only from nuclear reactions
Thermal energy
flows from hot objects to cooler ones
GPE
possessed by anything that can fall
EPE
possessed by springs, elastic, rubber bands
Chemical
possessed by foods, fuels, batteries
What are gravitational and elastic potential and chemical energy?
Forms of stored energy
An appliance is more efficient if it…
wastes less energy
What happens to wasted energy?
It is always dissipated as heat
What are the energy transfers for a microphone to and amplifier to a speaker?
sound - electrical - sound
What does a TV transfer?
electrical - light and sound
What do toy car batteries transfer?
chemical - electric - kinetic, sound, heat, light
What does a batter charge transfer?
electrical to chemical
What are GPE and Potential energy always transferred to first?
kinetic energy
How will a Sankey diagram show if something is more efficient?
It will have thick arrow for the useful energy output
What does a filament lamp sankey diagram look like?
Most energy is wasted as heat; only small % is useful output
What is IR radiation?
transfer of heat energy by electromagnetic waves