Temperature And Heat Science Flashcards
What are the 3 methods of heat transfer?
Conduction
Convection
Radiation
Conduction occurs mainly in solids liquids or gases?
Mainly in solids
In what states of matter can conduction occur?
All states
Liquid, solid, gas
What is conduction?
The transfer of heat from one molecule to another by means of direct contact.
What is the primary method of heat conduction in pipe trades?
Conduction
What is the primary cause of heat loss in a building?
Conduction.
In what states of matter does convection occur?
Liquids and gases.
What is convection?
The transfer of heat within liquids and gases through differences in densities.
Hot water tanks use what to transfer water through baseboard heaters?
Convection
What is a negative effect of convection?
Unwanted circulation
What is radiation as it applies to heat transfer?
The transmission of heat energy through a space by means of electromagnetic infrared rays.
At what point do inferred rays transfer their heat?
When they strike a substance
When infrared rays strike a substance what kind of heat is it transformed to?
Sensible heat.
What can radiant heat travel through?
Transparent and translucent solids liquids or gases. Just like light. And slightly warms the translucent material as it passes through.
What is a good reflector by poor absorber of heat?
Light colored, shiny surfaces.
What surfaces are excellent absorbers and emitters of heat?
Dark, rough surfaces
In a hot water tank where would the liquid with the greatest density be found?
Bottom
In a hot water tank the more dense water is warmer or cooler?
Cooler
At what temperature is water most dense?
4 C
39 F
From 4C to 100 C how much does water expand?
5%
How much does water expand when it vaporizes?
About 1700 times
When cooled lower than 4c does water contract or expand?
Expands
When turned to ice how much does water expand by?
7.5%
What is the formulae for rate of expansion?
Length X Delta T (temperature change) X coefficient of expansion
Insulation on piping helps prevent what type of heat transfer?
Heat loss due to conduction
