All About Energy Transfer Flashcards
What are the 7 main energy stores (mickee g)
Magnetic, internal (thermal), chemical, kinetic, electrostatic, elastic potential and gravitational potential
What is magnetic energy and give an example
The energy stored when repelling poles have been pushed closer together or when attracting poles have been pulled further apart eg fridge magnets
What is internal (thermal) energy
Thermal energy is produced when the atoms and molecules in a substance vibrate faster due to a rise in temperature eg boiling water on a stove
What is chemical energy with an example
The energy stored in chemical bonds such as those between molecules eg foods
What is kinetic energy with an example
The energy of a moving object eg a comet
What is electrostatic energy with an example
The energy stored when repelling charges have been moved closer together or when attracting charges have been pulled further apart eg the attraction of plastic wrap to your hand after being removed from a package
What is elastic potential energy with examples
The energy stored when an object is stretched or squashed eg compressed springs
What is gravitational potential energy with an example
The energy of an object at height eg kites
What is nuclear energy with an example
The energy stored in the nucleus of an atom eg nuclear reactors
What are the four types of energy transfer
mechanical work - a force moving an object through a distance
electrical work - charges moving due to a potential difference
heating - due to temperature difference caused electrically or by chemical reaction
radiation - energy transferred as a wave, eg light and infrared - light radiation and infrared radiation are emitted from the sun
Dissipated definition
The spreading out and transfer of energy stores into less useful forms often referred to as ‘wasted energy’
Give an example of dissipation
for a tumble dryer, the electrical work is transferred into useful internal (thermal) energy which helps to dry clothes - energy is dissipated by sound waves
What is the law conservation of energy
energy can neither be created nor destroyed - only converted from one form of energy to another.
What is kinetic energy measured in
Joules
What is elastic potential energy measuered in
Joules
Define work done in terms of energy
Work is done when energy is transferred from one store to another its calculated as work = force x distance
Define efficiency in the context of energy
Efficiency measures how well a system converts energy input into useful output calculated using (Useful power output / energy input) x 100
How does energy transfer occur between different stores
Energy transfer happens when energy moves from one store to another
What factors determine the gravitational potential energy of an object
The objects mass height and the strength of the gravitational field
What factors influence kinetic energy
Mass and velocity of the object
How is energy dissipated in various processes
Energy is often dissipated as thermal energy due to friction or as sound energy during collisions
What happens in electrical appliances
Electrical appliances convert electrical energy into various forms such as heat light or sound
How is power related to energy transfer
Power is the rate at which energy is transferred or transformed calculated by energy transferred / time taken
How is energy transfer by heating defined
Energy transfer by heating is the process of transferring thermal energy from a hotter object to a cooler one
