Big Idea 11:
Energy and Energy Transformation
Big Idea 6: Earth in Space
Topic 8: Heat
Benchmarks
SC.3.E.6.1 Demonstrate that radiant energy from the Sun can
heat objects and when the Sun is not present, heat may be lost.
SC.3.P.11.1 Investigate, observe, and explain that things that give
off light often also give off heat.
SC.3.P.11.2 Investigate, observe, and explain that heat is
produced when one object rubs against another, such as rubbing
one’s hands together. Identify common materials that conduct
heat well or poorly.
SC.3.N.1.1 Raise questions about the natural world, investigate
them individually and in teams through free exploration and
systematic investigations, and generate appropriate explanations
based on those explorations.
SC.3.N.1.6 Infer based on observation.
SC.3.N.3.2 Recognize that scientists use models to help
understand and explain how things work.
What do fire, sunlight and the
rubbing of hands have in common?
Chemical energy changes
into heat energy when
wood burns.
Light energy from the
sun changes into heat
energy when it hits
Earth.
They all produce heat
Energy of motion
changes into heat
energy when hands
are rubbed together.
energy.
What is Heat Energy?
• Heat energy is the energy of moving particles in any
kind of matter.
What happens in Heat Energy?
• When any form of matter gets warmer, the moving
energy of its atoms increases.
• The object’s particles move faster, so its heat energy
increases.
• A change in heat energy can lead to a change in phase
or state of matter:
- Ice melts from a solid to a liquid.
- Liquid water changes to water vapor.
How is it measured?
• Temperature is a measure of heat energy.
• A thermometer is the tool used to measure
temperature.
How does a thermometer work?
Let’s practice reading a thermometer
◦F = degrees Fahrenheit
◦C = degrees Celsius
Look around the room:
What are some sources of light and heat?
Group 1
Things that give off light
Light Sources
Sunlight through the windows
Ceiling lights
Computer screens
LCD projector
Flashlight
Group 2:
Things that give off heat
Heat Sources
Sunlight
Lamps
Stove burners
Candle flame
Hot water
Toaster oven
Objects rubbing together
How many light and heat sources are the same?
What are some examples of objects rubbing
against each other and producing heat?
Draw and/or write some examples in your notebook
How does sunlight affect the
temperature of water?
Hypothesis: If a cup of water is placed in the
sun and a second cup of water is placed in the
shade each for 30 minutes, the cup of water in
the sun will have a (higher, lower or the same)
temperature.
Materials per group: 2 plastic clear cups
water marker 2 thermometers measuring cup
First let’s practice reading a thermometer
Procedures
1. Label 1 plastic clear cup Sunlight.
Label the other plastic clear cup No Sunlight.
2. Use a measuring cup to measure ½ cup of water.
3. Pour the ½ cup of water into the cup labeled
Sunlight.
4. Repeat steps 2 and 3 for the cup labeled
No Sunlight.
5. Draw a data table in your science notebook.
Difference
Procedures continued
6. Place a thermometer in each cup. Wait two minutes.
Measure and record the beginning temperature of each
cup of water on a data table in your notebook.
7. Place the Sunlight cup in the sun.
Place the No Sunlight cup in the shade.
8. Wait 30 minutes. Repeat step 5. to measure and record
the ending temperature for both cups.
9. Find the difference between the beginning
temperature and the ending of both and record on the
data chart. Compare their temperatures.
Difference
Explain the Data:
1.What did you do?
I compared the temperature of water placed in the sun to
water placed in the shade after 30 minutes.
2.What happened to the temperature of the water in the
sunlight? Why?
The temperature of water in the Sunlight cup became
warmer than the water in the No Sunlight cup because when
the water absorbed the sunlight’s radiant energy, it transfers
to heat energy and heats the water.
More Explorations
Question: What happens to water and soil when
they go in and out of sunlight?
Predictions:
Hint
Materials per group (trial):
soil water
2 thermometers
2 same size clear containers
Procedures
1. Put a container of water and a container of soil in
the shade. Measure the beginning temperature of
both. Record.
2. Wait 15 minutes. Measure and record the
temperature of both on the data table.
3. Take those two containers and place both in full
sunlight.
4. Wait 15 minutes. Measure and record the
temperature of both on the data table.
5. Take those two containers and place both back shade.
4. Wait 15 minutes. Measure and record the
temperature of both on the data table.
More Explorations Data
Time
Shade
15 min.
Sun
15 min.
Shade
15 min.
Water
Temperature
Soil
Temperature
Explain the Data
More Explorations
1. What was the temperature difference of the soil
in the shade and the soil in the sun? (Show your work.)
2. What was the temperature difference of the soil
in the shade and the soil in the sun? (Show your work.)
3. Make a graph of your data.
4. Is this statement true or false:
The sun heats the Earth?
How do you know?
5. What are you wondering now?
Radiant Energy – Solar Energy
As the Earth
Day
As the Earth
rotates, one side is
turning away from
the sun and stops
receiving the sun’s
radiant light energy
and the transfer
into heat energy,
becoming cooler
during night time.
Night
rotates on its
axis, the side
facing the sun
absorbed the
sunlight’s radiant
energy, which
transfers to heat
energy and
heats the Earth
during daylight
hours.
You Tell Me???
Which of these pictures is receiving more light energy from
the sun?... more heat energy from the sun? Why?
1.
3.
1
2.
REVIEW Questions
1. Give some examples of objects that produce
heat.
2. Give some examples of objects that give off
light and heat.
3. Why do people rub their hands together
when they feel cold?
Build a Solar Oven
You can use the sun's energy to heat up a tasty treat with this
simple solar oven!
Materials:
• Cardboard pizza box (the kind delivered pizza comes in)
• Box knife or scissors
• Aluminum foil
• Clear tape
• Plastic wrap (a heavy-duty or freezer zip lock bag will also work)
• Black construction paper
• Newspapers
• Ruler, or wooden spoon
Click on link below for recipes ideas:
Solar Oven Recipes PDF
What to do
1.
2.
3.
4.
5.
Use a box knife or sharp scissors (with an adult’s help) to cut a flap in the lid of
the pizza box. Cut along three sides, leaving about an inch between the sides
of the flap and the edges of the lid. Fold this flap out so that it stands up when
the box lid is closed.
Cover the inner side of the flap with aluminum foil so that it will reflect rays
from the sun. To do this, tightly wrap foil around the flap, then tape it to the
back, or outer side of the flap.
Use clear plastic wrap to create an airtight window for sunlight to enter into
the box. Do this by opening the box and taping a double layer of plastic wrap
over the opening you made when you cut the flap in the lid. Leave about an
inch of plastic overlap around the sides and tape each side down securely,
sealing out air. If you use a plastic bag, cut out a square big enough to cover
the opening, and tape one layer over the opening.
Line the bottom of the box with black construction paper - black absorbs heat.
The black surface is where your food will be set to cook.
To insulate your oven so it holds in more heat, roll up sheets of newspaper and
place them on the bottom of the box. Tape them down so that they form a
border around the cooking area. The newspaper rolls should make it so that
the lid can still close, but there is a seal inside of the box, so air cannot escape.
What to do – Part 2
6. The best hours to set up your solar oven are when the sun is high overhead from 11 am to 3 pm. Take it outside to a sunny spot and adjust the flap until
the most sunlight possible is reflecting off the aluminum foil and onto the
plastic-covered window. Use a ruler to prop the flap at the right angle. You
may want to angle the entire box by using a rolled up towel.
7. You can make toast by buttering a slice of bread, or sprinkling cheese on it,
then letting the sun do the rest. Cooking a hot dog or making nachos with
chips and cheese are also fun treats to make in your solar oven! It would also
work great to heat up leftovers. So the paper at the bottom doesn't get dirty,
put what you would like to cook on a clear plastic or glass plate. A pie plate
would work well.
8. To take food out of the oven, open up the lid of the pizza box, and using oven
mitts or potholders, lift the glass dish out of the oven.
Few tips for having success with your solar oven:
•
Move your solar oven when needed, so that it faces direct sunlight. You
should be checking periodically on your oven, to make sure it is in the sun.
•
Make sure that the foil-covered flap is reflecting light into the pizza box,
through the plastic-covered window.
What's happening?
• The heat from the sun is trapped inside of your pizza box solar oven, and it
starts getting very hot. Ovens like this one are called collector boxes,
because they collect the sunlight inside. As it sits out in the sun, your oven
eventually heats up enough to melt cheese, or cook a hot dog! How does
it happen? Rays of light are coming to the earth at an angle. The foil
reflects the ray, and bounces it directly into the opening of the box. Once
it has gone through the plastic wrap, it heats up the air that is trapped
inside. The black paper absorbs the heat at the bottom of the oven, and
the newspaper make sure that the heat stays where it is, instead of
escaping out the sides of the oven.
• Your solar oven will reach about 200° F on a sunny day, and will take
longer to heat things than a conventional oven. Although this method will
take longer, it is very easy to use, and it is safe to leave alone while the
energy from the sun cooks your food. If you do not want to wait long to
have a solar-cooked dish, try heating up something that has already been
cooked, like leftovers, or a can of soup. Putting solid food in a glass dish
and liquids in a heavy plastic zip lock bag works well. You can also pre-heat
your oven by setting it in direct sun for up to an hour.