ENERGY Flashcards
Name 8 energy stores
Kinetic, gravitational potential, elastic potential, thermal, chemical, nuclear, magnetic, electrostatic
Name 4 ways in which energy can be transferred
Heating, waves, electric current and mechanically
What is a closed system
A system where no energy can be transferred to our from the surroundings - total energy stays the same
What is work done
energy transferred when a force moves an object
What is one joule of work
The work done when a force of 1N causes an object to move 1m in the direction of the force
Describe the energy transfer when a ball is fired using an elastic band
Energy is transferred mechanically from the elastic band to the kinetic store os the band - some energy is dissipated to the surroundings as thermal energy
What does a materials thermal conductivity tell you
How well it conducts heat
Which materials how low thermal conductivity
Thermal insulators
3 factors that determine the rate of thermal energy transfer through a material
thermal conductivity, temperature difference and thickness of material
What factors affect the rate of heat loss from a building
Thickness of walls and roof, thermal conductivity of walls and roof
Define specific heat capacity
Amount of energy requires to raise the temperature of 1kg of a material by 1 degree Celsius
What is infrared radiation
Type of electromagnetic radiation
Compare the amount of infrared radiation emitted and absorbed by an object that is increasing in temp
More infrared radiation absorbed than emitted
What is a black body
Theoretical object that absorbs 100% of the radiation that falls on it and does not reflect or transmit any radiation
Why do greenhouse gases increase the Earth’s temp
Earths surface absorbs and re emits radiation from the sun which greenhouse gases then absorb - they re emit this radiation back towards earths surface
