Topic 1- Energy Flashcards
(27 cards)
What is a system?
A single object or a group of objects
What happens when a system changes and how is it transferred?
Energy is transferred
It is transferred in or away from the system between different object in the system or different types of energy stores
What is a closed system?
Systems were neither matter nor energy can Emeterio or leave
What is the net change in total energy in a system ?
Zero
What is work done and when can it be done?
Is is another way of saying energy transferred
Can be done when current flows or by a moving object
What is specific heat capacity ?
The amount of energy needed to raise the temperature of 1kg it a substance by 1oc
What is the conservation of energy ?
Energy can be transferred usefully, stored or dissipated but can never be created or destroyed
What is power ?
The rate of energy transfer or the rate of doing work
What is a powerful machine ?
A machines which transfers a lot of energy in a short space of time
What is conduction ?
The process where vibrating particles transfer energy to neighbouring participles
What is thermal conductivity?
Measure of how quickly energy is transferred through a material in this way
What is convection ?
Where energetic particles move away from hotter to cooler regions
Where can convection happen ? And how is energy transferred
Gases and liquids
Energy is transferred by heating to the thermal store of the liquid or gas
What causes energy in a system t be dissipated ?
When something moves, at least one frictional force acts against it
What way can friction be reduced?
Lubrication
Name ways to reduce heat loss in a house ?
Cavity walls-> air gap reduces amount of energy transferred
Lost insulation
Double glaze windows
Fraught excluders -> around doors
Why are useful devices useful ?
Because they can transfer energy from one store to another
Why is a device said to be efficient?
The less energy wasted in the energy store
How can u improve efficiency of an object?
Insulating objects
Lubricating
Making them streamline
Where is energy transferred to as they can never be 100% efficient ?
Useless thermal energy stores
Name the non renewable energy stores
Coal
Oil
Natural gas
Define non renewable energy stores
Fossil fuels and nuclear fuel, natural resources that form underground over millions of years
How do non renewable energy resources provide energy ?
Burnt
What are the important things about non renewable energy resources ?
They will all run out one day
They do damage to the environment
Provide lost our energy
