Vacuum flask Flashcards
1
Q
What heat transfer is prevented in a vacuum flask
A
Conduction and convection as it has a tight lid and insulation which prevents heat transfer. It contains a hollow area where there are no particles, therefore no heat transfer as it must occur by direct particle to particle contact.
2
Q
How does a thermos work
A
Air is removed from the space in-between the walls meaning there are no particles inside. There is a tight lid and insulation which prevents heat transfer by conduction and convection as there is no direct particle contact. There is a silvered inside that reflect heat rays that try to escape.
