Topic 1 Energy Flashcards
Kinetic energy
1/2 x mass x velocity*2
Elastic potential
1/2 x spring constant x extension*2
Gravitational potential energy
Mass x height x gravity
Earth is 9.8n/kg
Define specific heat capacity and state the equation
Amount of energy required to raise the temperature of 1kg of a substance by 1•c
Change in thermal energy = mass x specific heat capacity x change in temperature
State equations for efficiency
Useful output energy transfer/ total energy input transfer
Useful power output/ total power input
Define power
Rate of which energy is transferred of which work is done
State equations of power
Work done/ time
Energy transferred/ time
State the principle of energy conservation
Energy can be transferred usefully, stored or dissipated but not created or destroyed
Explain what happens to energy transfers in a closed system
Closed systems are when Northern matter or energy can enter or leave
Explain how unwanted energy transfers can be reduced between working parts
Lubrication reduced frictional forces
What happens when a materials conductivity levels are higher
The higher the thermal conductivity of a material the height rate of energy transfer
Explain conduction and convection
Conduction is the process where vibrating particles transfer energy to neighbouring particles.
Cavity wall insulation, double glazing and drought excluders all reduce the energy transfers
Convection is where energetic particles move away from hotter regions to cool regions
Radiators
What is a renewable energy source
A renewable energy source is one that is being (or can be) replenished
What are the main available energy sources
Coal, oil, gas
What energy sources are used for transportation and heating
Transport=. Coal petroleum diesel
Heating = natural gas, coal, solar water heaters
