heat transfer Flashcards
does the mass remain same?
yes, the mass remains the same during expansion or contraction
change of density
- density of object decreases when an object expands
- dist between particles change
bimetallic strip
- brass expands / contrast faster then iron
arrangement of bimetallic strip
- brass on top of iron ( expansion)
- brass below iron (contraction)
fire alarm
- fire causes bimetallic strip to expand
- brass expands faster then iron
- strip bends towards and touches contact point
heat transfer from?
hotter to colder region
which state can conduction occur in
solid liquid gas
conduction
Conduction is the transfer of heat through a medium without the movement of the particles in the medium
what does “ transfer of heat through a medium “ mean
heat is traveling through something, like a material or substance
convection
transfer of heat through a medium by the movement of particles in a medium
which state can convection be in
liquid and gas
convection current
When the water gains heat, it expands and its density decreases so it rises up while the cooler water sinks to replace the heated water as it is denser. This is then repeated to form a convection current
radiation
heat moves without needing any material to travel through.
It happens when something gives off energy in the form of invisible waves, called infrared radiation.
radiation VS convection
radiation travel in empty space
convection requires air and water
absorber
takes in heat or energy from radiation.
