Energy Flashcards
What is a system?
A single or a group of objects
What is a closed system?
Where neither matter or energy can leave the system
What are the eight types of energy?
Thermal, kinetic, gravitational potential, elastic potential, chemical, magnetic, electrostatic and nuclear
What are two ways energy can be transferred?
By heating or by doing work
When can work be done?
When current flows or by a force moving an object
Why do raised objects store energy in gravitational potential energy stores?
Because lifting an object in a gravitational field requires work, which causes a transfer of energy
What happens when an object falls, in terms of energy?
Energy from its gravitational potential store is transferred it it’s kinetic energy store. if there’s air resistance, then some of the energy can be transferred to other energy stores
What is specific heat capacity?
The amount of energy needed to raise the temperature of 1kg of substance by 1C
What is the conservation of energy principle?
Energy can be transferred usefully, stored or dissipated but can never be created or destroyed
What is dissipated energy?
Where the energy is being stored in a way that is not useful
What is power?
The rate of doing work or the rate of energy transfer
What is conduction?
The process where vibrating particles transfer energy to neighbouring particles
What is convection?
Where energetic particles move away from hotter to cooler regions
How is a device more efficient?
If less input energy transferred to an energy store is wasted
How do you work out efficiency?
Useful output energy transfer / total input energy transfer or useful power output / total power input
What are the three main fossil fuels?
Coal, oil and natural gas
What is a non-renewable energy resource?
Resources that will run out one day
What are the seven renewable energy resources?
Solar, wind, water waves, hydro-electricity, bio-fuel, tides and geothermal
What is a renewable energy resource?
Resources that will never run out
Why are non-renewable sources better than renewable ones?
They provide more energy and are more reliable
Why are renewable sources better than non-renewable ones?
They do less damage to the environment and will never run out
