The document discusses the three main types of heat transfer: conduction, convection, and radiation. Conduction involves the direct transfer of kinetic energy between particles in contact with each other, such as a metal spoon in hot chocolate. Convection involves the circulation of heated particles within fluids like liquids and gases. Radiation transfers heat through electromagnetic waves and does not require the movement of particles.

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