Thermal energy Flashcards
Define heat
Energy transfered from one object to another as a result of a difference in temperature.
Define temperature
Measure of the temperate and the average kinetic energy of a substance
Describe the difference between heat and temperature
Heat is a form of energy whilst temperature is a measure of energy/hotness or coldness
Define the three methods of heat transfer
Conduction
Convection
Radiation
Define conduction
The transfer of heat by direct particle to particle contact without particles moving from their place
What matter does conduction occur in
Solids as particles are tightly packed - particles must be touching for conduction to occur
Describe the process of conduction
The particles are packed tightly and vibrate constantly
Thermal energy is transferred to the particles - the hotter the particles the more kinetic energy produced
The kinetic energy is transferred from hot parts of the metal to cold parts by direct particle to particle contact
Convection
Where hotter less dense material rises and cooler dense material sinks under the influence of gravity
In what matter does convection occur
Liquids and gasses
Explain why solids, liquids and gases conduct heat differently
Because of their density as solids are tightly packed whereas liquids are separated
Define radiation
Transfer of heat through electromagnetic waves.
Describe the process of radiation
Heat waves emitted and may be either absorbed, reflected or transmitted to a colder body/surface
-> Sun heats earth by electromagnetic waves. Bodies emit heat waves
Identify colours that are more likely to absorb, reflect or transmit radiation
Dark colours absorb radiant heat
Light colours reflect radiant heat
Clear materials transmit radiant heat
What colours absorb radiant heat
Dark colours
What colours reflect radiant heat
Light colours
