UNIT 2 – CHAPTER 6

HEAT TRANSFER

Science 7

KEY TERMS

Page 174

3 P RO C E SS ES O F H E A T T R A N S F ER

1. Conduction

The transfer of thermal energy that occurs when warmer particles come in

contact with cooler particles and transfer energy to the cooler particles.

Usually in solids

A hot burner particles collide with cooler particles in the pan and then transfer

the kinetic energy

Vibrations occur, and collide and then transfer energy

PARTICLES DO NOT LEAVE THEIR POSITION !

ACTIVITY 6-2A

Page 193

3 P RO C E SS ES O F H E A T T R A N S F ER

2. Convection

The process in which a warm liquid or gas moves from one place to

another, carrying

heat with it

Convection Currents –

patterns of movement of

heat EX: Wind

Note: Important diagram on page 177 (candle)

ACTIVITY 6-1B

DISPLACED DROPS

Page 179

3 P RO C E SS ES O F H E A T T R A N S F ER

3. Radiation

Radiant energy is carried by waves instead of particles. Energy carried by the

waves turn into kinetic energy from the water.

Waves are the floating objects will receive kinetic energy from the water.

Light waves and some other forms of waves are called electromagnetic waves.

Radiation – the transfer of energy carried by electromagnetic waves.

Absorbing Radiant Energy

- when the surface of an object absorbs the electromagnetic wave

energy, it becomes warmer.

TYPES OF RADIATION

Types:

• Radio

• Micro

• Infrared

• Visible

• Ultraviolet

ACTIVITY 6-1C

ENERGY TRANSFERS &

HOME HEATING SYSTEMS

Page 182

READING CHECK

Page 170 – Checking Concepts - # 1,2

Page 185 # 2,3

HEATING HOMES

Convection currents help heat the homes, the air circulates .

Wood stoves are black which makes them more efficient for

radiators.

3 TYPES OF HOME HEATING:

Oil/Gas Heating - Air moves into the

furnace and fans blow the hot hair back into the

house (often through ducts)

Water Heating - pipes pump hot water

through them

Air-Air Heating – heat from the ground

(forest Center at SWGC)

CHECKING CONCEPTS

Page 191 - # 1,2,3,6,7,9,10

CONDUCTORS & INSULATORS

Cookware

Thermal Conductivity – rate at which substance conducts heat is

called.

Copper is a good heat conductor (like in the bimetallic strip) often

the bottoms of pots are copper so they heat up faster.

Stainless steel is a poor conductor, so they add copper to the

bottom.

CookwareThermal Conductivity – rate at which substance conducts heat is called.

Copper is a good heat conductor (like in the bimetallic strip) often the bottoms of pots are copper so they heat up faster.

Stainless steel is a poor conductor, so they add copper to the bottom.

CONDUCTORS & INSULATORS

Radiators

CookwareThermal Conductivity – rate at which substance conducts heat is called.

Copper is a good heat conductor (like in the bimetallic strip) often the bottoms of pots are copper so they heat up faster.

Stainless steel is a poor conductor, so they add copper to the bottom.

Car Radiator Home Radiator

CONDUCTORS & INSULATORS

Insulators

best insulator is nothing, in this case, a vacuum

true vacuum is not possible

partial vacuum, like a thermos, is a great example

inside the thermos is double class wall where the air was removes

then sealed

CookwareThermal Conductivity – rate at which substance conducts heat is called.

Copper is a good heat conductor (like in the bimetallic strip) often the bottoms of pots are copper so they heat up faster.

Stainless steel is a poor conductor, so they add copper to the bottom.

INSULATING YOUR HOME…

Insulating your home

a sod hut, like in L’Anse aux Meadows was traditional form of heating

homes

thick layers of sods kept the heat inside and the cold outside in the winter

Cost of fuel for heating homes are expensive – houses naturally leak some

heat and then it is replaced

Insulation that is found in our house walls traps the air and prevents it

from moving EX: fiberglass

R-Value Chart p.198

Windows are the places where greatest heat is lost

Your sweater/jackets are your body’s insulators

Reading Check page – 198 - # 1-3

Checking Concept – page 205 - #1,4,5

TEMPERATURE VS. HEAT

Large bodies of water has a major effect on climate.

Temperatures of substances respond when heated or cooled.

The amount of water does not change the temperature.

ACTIVITY 6-3A

Page 207

THERMAL ENERGY

Absorbing and loosing heat

Sun Water and Solid Ground

Reading Check – page 211 - # 2,4

Checking Concepts page 215 - #1,6,9

Checking Concepts – page 216 - # 1a,b,c, 2, 3, 4, 12 ,13

FOR OUR CORE LAB NEXT CLASS!

YOU ARE REQUIRED TO BRING:

ONE DARK POP CAN – COKE ZERO OR PEPSI

ONE LIGHT POP CAN – DIET COKE OR DIET ROOT BEER

CORE LAB

Page 184