Heat Transfer Flashcards
Heat energy is _____ from the _____ of an object.
1) Radiated
2) Surface
The _____ the surface area, the _____ can be emitted, so the _____ the transfer of heat.
1) Bigger
2) More infrared waves
3) Quicker
Why do cars and motorbikes often have fins?
The surface area is increased so heat is radiated away quicker. (Engine cools quicker)
Heat sinks are…
Devices designed to transfer heat away from objects
Large surface area
An object with a smaller volume but the same surface area and temperature will…
Cool more quickly (more of the object in contact with surroundings)
A vacuum flask reduces heat energy transfers by…
Double-walled with vacuum (stops conduction and convection through the sides)
Walls either side of vacuum are silvered (minimises radiation)
Insulating foam (minimises heat conduction)
Stopper made from plastic filled with cork or foam (reduce conduction)
Hair on your skin and fur reduces heat loss by…
Convection
When too warm, more blood flows near the surface your skin so more heat can be lost by…
Radiation
Animals in cold areas have small ears to minimise heat loss by…
Radiation
Animals in hot areas have large ears to allow them to lose heat by…
Radiation
