• HOW WOULD YOU DESCRIBE HEAT? HAVE YOU EVER BEEN HOT OR COLD?

• I can demonstrate how things become hot or cold.

Heat Transfer

How does heat move?

What is energy & temperature

◼Everything is made up of

Atoms

◼Atoms are the building blocks

◼Atoms are always in motion –

they’re always moving

◼How fast atoms move

depends on their state.

◼ In a solid the atoms are

moving very slowly.

◼In a liquid they are moving a

little faster.

◼In a gas they are moving even

faster.

◼ Temperature also affects

how fast the atoms are

moving. The higher the

temperature the faster the

atoms are moving.

What do you notice about the

molecules in each state of matter?

◼ Temperature is the

average amount of energy

of motion of each

molecule of a substance.

We think of it as how hot

or cold something is

What is TEMPERATURE

• Temperature is a measure of how hot or cold something is; specifically, a measure of the average kinetic energy of the particles in an object,

◼Thermometer is used to

measure temperature. It works

because liquids expand when

they heat up (moves the liquid

up the glass tube) and contract

when they cool (liquid moves

down the glass tube)

Thermometer

Transfer of Heat (Thermal) Energy

• Heat (thermal energy) is transferred from one object to another when the objects are at different temperatures.

• Thermal energy always moves from warmer to cooler objects

Conductors and Insulators

• Substances that transfer thermal energy very well are called Conductors.

• Substances that do not transfer thermal energy very well are called Insulators.

How does heat move?

◼There are three ways in

which heat moves:

radiation, conduction, and

convection

Radiation

◼This is the simplest form of heat

transfer; heat moves by waves.

With radiation, heat is carried

by electromagnetic waves.

Radiation

Radiation

Radiation

Eureka video clip:http://www.youtube.com/watc

h?v=2JZciWtK6vc

http://www.pbslearningmedia.org/asset/lsps07_int_heattransfer/

https://www.e-education.psu.edu/egee102/node/2053

Scroll down for animations

Animations of Heat Transfer

Conduction

◼Heat is transferred by two

bodies that are in contact with

each other. Heat ‘flows’ from

one object to the other. The

heat is moving between those

objects.

Conduction

Conduction• Conduction is the

transfer of heat by direct contact (particles collide)

• Conduction occurs most easily in solids and liquids

Conduction

Eureka Video clip:http://www.youtube.com/watch?

v=Yitiw6Y7xZg

Animation: http://www.passmyexams.co.uk/GCSE/p

hysics/conduction-heat-transfer.html

Your turn…Explain the movement of thermal energy if you were about to eat the Chinese food below. How is this an

example of Conduction?

Convection

◼Hot portions of a fluid move through the fluid itself. The hot part of the fluid mixes with the cold part of the fluid and transfers the heat. This is the most efficient form of heat transfer.

Everyday Examples of Convection Currents

http://www.healthyheating.com/Definitions/heat-

transfer-convection.htm#.VD7SIfmjOSo

http://www.passmyexams.co.uk/GCSE/physics/convection-heat-transfer.html

Animations and Video Clips

Convection

Eureka Video clip:

http://www.youtube.com/watch?v=ON2Y3FEk_UI

Describe an example of convection that you have experienced recently

at home, at school, or outside.

Convection

How Hot was it? Dashboard Oven

Hot

What cooked the cookies?

Examples of Heat

Transfer

What We Know So Far

◼Everything is made up of atoms

which are always moving

◼Temperature can make atoms

move faster or slower

◼Heat can move in three different

ways: radiation, conduction

and convection.