CORNELL NOTES ABOUT HEAT AND HOW
HEAT TRANSFERS
Essential Question #1: What is heat
and how does it differ from
temperature?
Essential Questions #2: What are
the methods of heat transfer and
how does each one work?
WHAT IS HEAT?
•
A form of energy that flows between two samples of matter because of the differences in
temperature. Heat always flows from areas of HOT TO COLD.
WHAT IS THE DIFFERENCE BETWEEN HEAT AND
TEMPERATURE?
• Heat is the total amount of energy transferred in
systems due to a difference in temperature,
while temperature is a measure of how fast
molecules are moving in a substance (how much
heat is present). Thermal energy is related to
temperature. A substance can have thermal
energy with no heat (because particles in atoms
are always moving and this is thermal energy)
3 METHODS OF HEAT TRANSFER:
• 1. Conduction- the transfer of heat from one molecule
in a substance to another by means of DIRECT
CONTACT of the molecules (occurs in solids).
• 2. Convection- the transfer of heat in liquids or gases
due to currents. These currents are caused by
differences in density due to differences in temperature
(creating up and down currents).
• 3. Radiation- heat transfer that travels through space
and can move THROUGH something.
IMAGES OF EACH TYPE OF HEAT TRANSFER
EXAMPLES OF EACH TYPE OF HEAT TRANSFER
•
CONDUCTION:
-Touching a stove and being burned
-Ice cooling down your hand
-Boiling water by thrusting a red-hot piece of iron into it
•
-when computer on for long time, when your feet touch hot sand, when you touch a generator,
when you touch a light bulb that gives off heat
•
Convection:
when you turn on hot sink water
boiling water
hot spring water
rising, warm air
•
RADIATION:
-Heat from the sun warming your face
-Heat from a lightbulb (not direct contact)
-Heat from a fire
-Heat from anything else which is warmer than its surroundings.