1. Mr. Ilko

2.  Inthe previous sections we looked at heat
energy.
 This is energy that transfers from high
temperature to low temperature
 Conduction is an example of heat energy
taking place
 Conduction– is the transfer of energy
between two substances in contact

3.  Imagineyou have a metal spoon in a mug of
hot chocolate

4.  Becausethe particles inside the hot
chocolate are moving faster than those in the
spoon –energy gets transferred
 Thisenergy transfer will increase the speed
of the spoons particles increasing its own
temperature
 Theparts of the spoon not touching the hot
chocolate will slowly warm up as well

6.  Heat transfer only occurs in one direction
 Hot  Cold or
 High kinetic energy  low kinetic energy
 Kinetic energy means the amount of movement
 Conduction is most common in solids
 Less common in liquids
 RARE in gases

8.  Conductors – are materials that allow easy
transfer of heat
 Differentmaterials allow different amounts
of heat to be exchanged
 The better the conductor the more heat that can
be transferred
 Metal is a very good example of a GOOD
conductor

10.  Many solid items conduct heat, but not all
allow a lot to be transferred.
 Insulatorsare materials that Do Not allow
easy transfer of heat from a hot substance to
a cold substance
 Plastics, Cork and Wood are good examples of
INSULATORS

12.  Haveyou ever touched a pot on the stove
and burnt your hand?
 Curled your hair and touched the metal?
 Toavoid injury we commonly combine
Insulators & Conductors in order to create
tools we can safely use

19.  Heat is transferred when liquid or gas
particles move from one area to another.
 Inconvection the particles move, in
conduction only heat moves
 Convection ONLY occurs in liquids and gases

20.  Heat transfer by convection occurs when
particles in a liquid or gas move in a circular
pattern.
 These currents form when heat is transferred
to the liquid or gas

22.  When pot of water is placed on a hot stove the
heat from the stove travels through the
conductors and speeds up the particles in the
water
 The increased particle speed of the water on the
bottom causes the water to move to the surface
 This pushes the cooler water down to be heated
by the stove
 The water that moves away from the heat
slightly cools and the process repeats itself

23.  Heat moves only one direction
 From hot to cold
 Withthe air the circular motion still is
present
 The warmer air will rise pushing the colder
air down towards the heat and the cycle
continues

25.  The third form of heat transfer, only one that
does not rely on movement of particles
 Radiation is the transfer of energy through
invisible waves
 Some travel great distances, such as; The Sun
 Energy transferred from its source is called
Radiant Energy
 Heat is one type of energy, another is invisible
infrared waves

28.  When these waves hit an object the kinetic
energy (movement) increases
 Theparticles move faster and the object
becomes hotter.
 Every
hot object gives off some radiant
energy
 This is how you feel the heat of a stove without
touching it

30.  Have you every gone into a car that has been
sitting in the sun on a very hot summer day?
 What does it feel like?
 Whathappens when you touch the
dashboard?
 Thisis a result of the radiant energy from
the sun, transferring heat to the car

31.  Can anyone tell me why people tend to wear
more black clothes in the winter compared
to summer?
 Why does sand burn your feet when you walk
on it?

33.  Shinyor Light color objects reflect the
radiant energy
 Darkor dull color objects absorb radiant
energy