Conduction Convection Radiation Heat Transfer Slide 2 Heat
always moves from a warmer place to a cooler place. Hot objects in
a cooler room will cool to room temperature. Cold objects in a
warmer room will heat up to room temperature. Slide 3 Food for
thought If a cup of coffee and a red popsicle were left on the
table in this room what would happen to them? Why? The cup of
coffee will cool until it reaches room temperature. The popsicle
will melt and then the liquid will warm to room temperature. Slide
4 Heat Transfer Methods Heat transfers in three ways: Conduction
Convection Radiation Slide 5 Conduction the process of heat
transfer from one substance to another by DIRECT CONTACT Slide 6
Spoon Demonstration- Metal or Plastic? Slide 7 Create this table in
your notebook What do you think will happen? What actually
happened? Why? Metal Spoon Plastic Spoon Slide 8 Which spoon
conducts heat best? Which type of material is the best heat
conductor? Which material is the poorest conductor? Spoon
Demonstration- Metal or Plastic? Slide 9 Conduction When you heat a
metal strip at one end, the heat travels to the other end. As you
heat the metal, the particles vibrate, these vibrations make the
adjacent particles vibrate, and so on and so on, the vibrations are
passed along the metal and so is the heat. We call this? Conduction
Slide 10 Metals are different The outer e______ of metal atoms
drift, and are free to move. When the metal is heated, this sea of
electrons gain kinetic energy and transfer it throughout the metal.
Insulators, such wood and plastic, do not have this sea of
electrons which is why they do not conduct heat as well as metals.
lectrons Slide 11 Why does metal feel colder than wood, if they are
both at the same temperature? Metal is a conductor, wood is an
insulator. Metal conducts the heat away from your hands. Wood does
not conduct the heat away from your hands as well as the metal, so
the wood feels warmer than the metal. Slide 12 Conduction Mini-Lab
1. Send one person to get a cup of ice cubes and paper towels for
your table group. 2. You are going to hold the ice cube in your
hand over the paper towel. 3. In you ISN answer the following
questions: 1. In one sentence describe what happens to the ice
cube. 2. Does the heat transfer from your hand to the ice cube or
from the ice cube your hand? WHY? 3. How is this conduction? Slide
13 Join me at the lab table for a quick demonstration! Convection
Demonstration -Illustrate what you observed in 6 steps. -Explain
what you saw? -Why do you think this was happening? Slide 14
Convection the transfer of energy from place to place by the motion
of a liquid or a gas Slide 15 Convection What happens to the
particles in a liquid or a gas when you heat them? The particles
spread out and become less dense. This effects fluid movement. What
is a fluid?A liquid or gas. Slide 16 Fluid movement Cooler, more
d____, fluids sink through w_____, less dense fluids. In effect,
warmer liquids and gases r___ up. Cooler liquids and gases s___.
ense armer ise ink Slide 17 Water movement Hot water rises Cooler
water sinks Convection current Cools at the surface Slide 18 Why is
it windy at the seaside? Slide 19 Cold air sinks Where is the
freezer compartment put in a fridge? Freezer compartment It is put
at the top, because cool air sinks, so it cools the food on the way
down. It is warmer at the bottom, so this warmer air rises and a
convection current is set up. Slide 20 Convection questions Why are
boilers placed beneath hot water tanks in peoples homes? Hot water
rises. So when the boiler heats the water, and the hot water rises,
the water tank is filled with hot water. Why does hot air rise and
cold air sink? Cool air is more dense than warm air, so the cool
air falls through the warm air. Slide 21 Convection Mini-Lab In
your ISN: 1. Illustrate the lab set up and what you observed. 2.
List all materials used in this experiment. 3. Explain the movement
of the rheoscopic fluid. Why do you think this is happening? 4. How
can you relate this movement to what is happening in the
atmosphere? Hint: Use your Atmosphere Temperature graph to help you
answer this question. 5. In one sentence, write a concluding
statement about this lab using the word CONVECTION. Slide 22 Exit
Slip Can you think of any real world examples of convection???
Slide 23 Radiation- What is it???
http://www.youtube.com/watch?v=2JZciWtK6vc Slide 24 Radiation
energy that travels distances in the form of waves Slide 25 How
does radiation work?
http://www.pbslearningmedia.org/asset/lsps07_int_heattransfer/
Slide 26 The third method of heat transfer How does heat energy get
from the Sun to the Earth? There are no particles between the Sun
and the Earth so it CANNOT travel by conduction or by convection. ?
RADIATION Slide 27 Gases in the atmosphere can absorb radiation On
a sunny day objects around you look bright. Earths atmosphere
reflects or absorbs some sunlight, but allows most of the visible
light to pass through to Earths surface. A cloudy day is darker
because clouds reflect and absorb most of the sunlight, so less
light passes through to the ground. Slide 28 Atmosphere can affect
light in four ways It can absorb light reflect light let it pass
through emit or give off light Slide 29 Understanding the
Greenhouse Effect Certain gases in the atmosphere slow the energy
away from Earths surface. The gases absorb and emit the Earths
radiation which keeps energy in Earths system for a while. This
process is called the Greenhouse Effect. Slide 30 Understanding the
Greenhouse Effect How is wearing a jacket in the winter comparable
to the Greenhouse Effect? Slide 31 Radiation Mini-Lab 1. You will
roast a marshmallow using the radiation from a candle on your lab
station. 2. Go over safety procedures as a class. 3. Answer the
reflection questions in your ISN. 4. Eat a special treat- IF YOU
CATCH YOUR MARSHMALLOW ON FIRE YOU DO NOT GET TO EAT IT!! Slide 32
Radiation Mini-Lab Reflection Questions- Answer in COMPLETE
sentences! 1. Illustrate your lab set up and label all materials.
2. What type of heat transfer is taking place in this lab? 3. How
is the heat transferred to the marshmallow without touching the
flame of the candle? 4. Complete the following statement: If you
caught your marshmallow on fire this would be ______________, not
_______________. Slide 33 Title a page in your ISN Heat Transfer
Review Heat Transfer Review Slide 34 Slide 35 Slide 36 Quiz Number
your paper 1-5 Use the table you have just completed to help you
with the questions. This is to be done individually! Slide 37 1.
Which of the following is not a method of heat transfer?
A.Radiation B.Insulation C.Conduction D.Convection Slide 38 2. In
which of the following are the particles closest together? A.Solid
B.Liquid C.Gas D.Fluid Slide 39 3. How does heat energy reach the
Earth from the Sun? A.Radiation B.Conduction C.Convection
D.Insulation Slide 40 4. Which is the best surface for reflecting
heat radiation? A.Shiny white B.Dull white C.Shiny black D.Dull
black Slide 41 5. Which is the best surface for absorbing heat
radiation? A.Shiny white B.Dull white C.Shiny black D.Dull black
Slide 42 In groups you will classify each scenario into the proper
category using your knowledge of heat transfer. Heat Transfer
Challenge
