Presentation on theme: "TOPIC: Heat AIM: How is heat transferred?. What is heat transfer? Movement of heat from warm cool object Example = hot pan Heat moves from pan handle."— Presentation transcript:
TOPIC: Heat AIM: How is heat transferred?
What is heat transfer? Movement of heat from warm cool object Example = hot pan Heat moves from pan handle
3 types of heat transfer
1. Conduction Heat transfer in SOLIDS
Heat transfer by the direct contact of molecules
Fast moving molecules (have more heat) Bump into slower ones Start to move faster collide with other slower molecules…
Why can the girl on the right toast marshmallows without getting burned?
Conductor Material that allows heat to move through it easily Metals (copper & silver are the best)
Example: copper pipes (Heat exchangers in hot water tanks, under floor heating systems, and car radiators)
TOPIC: Heat AIM: How is heat transferred? Cont’d…
Insulators Do not conduct heat easily Wood, paper, wax, air, house insulation, plastic
2. Convection Transfer of heat in liquids & gases Liquid heated molecules move faster & farther apart less dense rise carrying heat with it
Example: warm air rises, cool air sinks
Convection currents Up & down movement of molecules due to changes in density
Convection Currents Inside the Earth
3. Radiation Heat transfer through space Can travel when no matter is present (vacuum) Heat energy from sun, stars, fire
Radiation from the Sun travels through empty space.
Radiation from the fire heats the marshmallow.
SOLIDS LIQUIDS & GASES THROUGH SPACE
A B C conduction radiation convection REVIEW
A B D convection radiation conduction REVIEW C convection