Section 4 - Heat Transfer Flashcards
What are the three ways heat energy can be transferred by?
Radiation, conduction, convection.
What is thermal (infrared) radiation?
It is the transfer of heat energy by electromagnetic waves.
What do you conduction and convection involve?
They both involve the transfer of energy by particles.
What is the main form of heat transfer in solids?
Conduction.
What is the main form of heat transfer in liquids and gases?
Convection.
Where does emission of thermal radiation occur?
Emission of thermal radiation occurs in solids, liquids and gases.
Any object can both absorb and emit heat radiation, whether or not conduction or convection are also taking place.
What is the link between temperature difference and heat transfer?
The bigger the temperature difference, the faster heat is transferred.
What does thermal radiation involved? How often does the radiation happen?
Thermal radiation involves emission of electromagnetic waves.
All objects are continually emitting and absorbing heat radiation.
Talk about thermal radiation when something cools down.
An object that is hotter than it surroundings emits more radiation than it absorbs (as it cools down).
Talk about what happens when something warms up.
An object that is cooler than it surroundings of those more radiation than it emits (as it warms up).
What happens when a solid warms up?
As the particles in a solid are held tightly together, this means that when one particle vibrates, it collides with other particles nearby and the vibration quickly passes from particle to particle.
The solid conducts the heat throughout, causing a rise in temperature throughout the solid.
Describe the conduction of heat process.
Conduction of heat is the process where vibrating particles pass on their extra kinetic energy to neighbouring particles.
