4 - 14 Energy transfers
Types of energy stores***
● Chemical energy
● Thermal energy (heat)
● Kinetic energy
● Sound energy (sound waves)
● Light (radiation)
● Electrical energy
● Nuclear energy
● Gravitational potential energy
● Geothermal energy (heat, from underground)
● (Elastic) Potential energy
● Magnetic energy
● Electrostatic energy
Types of energy transfers***
● Mechanically
● Electrically
● By heating
● By radiation (light, sound)
Energy transfers and conservation of energy
● ***Energy CANNOT be created NOR destroyed, but can ONLY be
transferred/changed from one form to another
● Examples of “wasted” energy:
○ Electric heater used to heat water in house, hot water stored in tank for use
when required; although tank is well-insulated, some energy will be
transferred from water and some will be used to heat up copper which tank is
made from - both processes mean some energy transferred from electricity to
heat is wasted, as does not do what we want it to do, not making water hot
(i.e.: “logic error”)
○ When filling car with petrol, main purpose is to transfer chemical energy
stored in fuel to kinetic energy (of car), with small amount doing other things,
e.g.: providing electrical energy for lights/radio; but process of transferring
energy not perfectly efficient, as not all energy used to do what we want
○ ***Unwanted energy transfers reduce efficiency (see below for efficiency)
1
Types of energy stores***
● Chemical energy
● Thermal energy (heat)
● Kinetic energy
● Sound energy (sound waves)
● Light (radiation)
● Electrical energy
● Nuclear energy
● Gravitational potential energy
● Geothermal energy (heat, from underground)
● (Elastic) Potential energy
● Magnetic energy
● Electrostatic energy
Types of energy transfers***
● Mechanically
● Electrically
● By heating
● By radiation (light, sound)
Energy transfers and conservation of energy
● ***Energy CANNOT be created NOR destroyed, but can ONLY be
transferred/changed from one form to another
● Examples of “wasted” energy:
○ Electric heater used to heat water in house, hot water stored in tank for use
when required; although tank is well-insulated, some energy will be
transferred from water and some will be used to heat up copper which tank is
made from - both processes mean some energy transferred from electricity to
heat is wasted, as does not do what we want it to do, not making water hot
(i.e.: “logic error”)
○ When filling car with petrol, main purpose is to transfer chemical energy
stored in fuel to kinetic energy (of car), with small amount doing other things,
e.g.: providing electrical energy for lights/radio; but process of transferring
energy not perfectly efficient, as not all energy used to do what we want
○ ***Unwanted energy transfers reduce efficiency (see below for efficiency)
1
