Name ____________________________________ Date __________________
LabQuest
Absorption of Radiant Energy
PRELIMINARY QUESTION
Does color affect the absorption of radiant energy? If it does, why would that matter to you? Write this
question in your journal and take 5 minutes to respond to it.
BACKGROUND INFORMATION
After conducting your investigation, research the topic of solar or radiant energy transfer and take notes in
your journal as time permits.
OBJECTIVES
In this experiment, you will
•
•
•
Monitor temperature change due to radiant energy absorption.
Calculate temperature changes.
Interpret your results.
MATERIALS
LabQuest
LabQuest App
2 Temperature Probes
lamp and bulb
piece of white paper
piece of black paper
tape
Science Journal
Figure 1
PROCEDURE
1. Tape two Temperature Probes to the table surface in the arrangement shown in Figure 1.
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Name ____________________________________ Date __________________
LabQuest
2. Place a piece of white paper over Temperature Probe 1 and a piece of black paper over Temperature
Probe 2 as shown in Figure 1.
3. Position a light bulb directly over the boundary between the two pieces of paper and about 10 cm above
the paper pieces. The bulb should be the same distance from both probe tips.
4. Connect Temperature Probe 1 to Channel 1 and Temperature Probe 2 to Channel 2 of LabQuest. Choose
New from the File menu. If you have older sensors that do not auto-ID, manually set up the sensors.
5. On the Sensor screen, tap Rate. Change the data-collection rate to 0.1 samples/second and the data
collection length to 600 seconds. Data collection will last 10 minutes.
6. Start data collection, then switch on the light bulb. Data collection will end automatically after 600
seconds (10 minutes).
7. When data collection is complete, turn the light bulb off and return all materials to the places directed by
your teacher.
8. Record your beginning and final temperatures.
a. After data collection is complete, a graph of temperature vs. time will be displayed. To examine the
data pairs on the displayed graph, tap any data point. As you tap each data point, the temperature
values of both probes are displayed to the right of the graph.
b. Identify the beginning and final temperatures for both Probe 1 and Probe 2. Record these values to
the nearest 0.1°C in your data table.
9.
Sketch or print the graph as directed by your teacher.
DATA
Probe 1
White
Probe 2
Black
Final temperature
°C
°C
Beginning temperature
°C
°C
Temperature change
°C
°C
PROCESSING THE DATA
1. In the space provided in the data table, subtract to find the temperature changes.
2. Which color had the larger temperature increase?
3. Which color had the smaller temperature increase?
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4. Would it matter if you wore dark clothing in the summertime? Why or why not?
5. Do you think clothing designers are concerned with heat transfer? Which decisions should a
designer make that are about heat transfer?
6. Solar collectors can be used to absorb the sun’s radiation and change it to heat. What color
would work best for solar collectors? Explain.
EXTENSION
1. Design an experiment to compare the radiant heat absorption of different colors. Perform the
experiment you designed. Remember to include the questions needed to process the data.
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TEACHER NOTES
This activity was modified from Vernier's Middle School Science LabQuest 6.
Goals and Outcomes:
NC Essential Standard: 6.P.3.1
Content Outcomes: Students will learn that different colors absorb radiant heat at different
rates.
Content Integration: ELA: Students write and draw in journals.
Math: Students will collect and organize, and graph data to compare
difference.
Process Skills:
infer
observe
collect and organize data
analyze and interpret data
evaluate choices
create (the extension for students who finish quickly)
Assessment:
Pre-assessment for this activity is simply to have students answer the preliminary question: Does
color affect how much heat a material will absorb?
Post assessment: students will journal using the ICE format of ideas, claims, and evidence. The
teacher may request students to use a 3-column table or paragraph format for this according to
teacher preference. Students should reflect upon their response to the preliminary question and
make changes as needed.
The teacher facilitates a short, whole class sharing of what students learned and how their ideas
changed.
Materials: (listed in the student sheet)
The number of students in a class and in each group will dictate how many light bulbs and sheets
of paper will be needed.
The number of Labquest stations available will dictate how many students are assigned to each
group. It is advisable not to exceed 4 students per group. 2-3 would be best.
Students will need access to their journals and the ICE format checklist as well as research notetaking guidelines. 2-column note-taking may offer an efficient format for research notes.
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Middle School Science with Vernier
Homework:
- Students could create a diagram or cartoon showing the process of transfer by radiant energy,
being sure to title, label, date, and name, with dialogue boxes explaining the process.
- Extension: Students can begin to design their wardrobe and describe the materials they would
use for each piece of clothing.
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Absorption of Radiant Energy
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Reading Selection from Rader's Geography4Kids.com
http://www.geography4kids.com/files/en_solarrad.html
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Radiant Energy From The Sun
Radiant energy is also called electromagnetic energy.
Almost every reaction that happens on the surface of the
Earth is the result of energy coming to the Earth from the
Sun. Radiant energy is also called electromagnetic energy
because it is made up of two combined fields. One of the
fields is electrical and the other is magnetic.
One other thing to remember: when we talk about incoming
radiation, we don't always mean radiation like X-rays, or
radioactivity. Light is radiation of some kind. All light is one
form of radiation or another. Just keep that in mind.
Constant Output Of Energy
Solar radiation is light energy from the Sun. So you've got the
Sun. Millions of kilometers away from the Earth it sits there
with all sorts of nuclear reactions going on. It's constantly
giving off a huge amount of energy and radiation. By the time
the energy and light reach Earth, there isn't much energy left.
Scientists have figured out something called a solar
constant. The constant is the amount of radiation that
actually hits the Earth. They say it's about 29.4 MJ
(Megajoules, a unit of energy) for every square meter for
each day.
Constant Input Of Energy
The flow of energy to the Earth is constant. That constant
flow is just the amount of EM radiation hitting the outside of
the atmosphere. The energy from the Sun has changed by
the time it hits the surface of the Earth. At the top of the
atmosphere you have the 29.4 MJ. We only see about 17 MJ
of energy at the surface of the Earth. Something had to
happen to the EM radiation between the top of the
atmosphere and the surface of the Earth. Energy and certain
types
of EM radiation (Infrared and Ultra Violet) have been
filtered away.
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Absorption of Radiant Energy
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Middle School Science with Vernier
Reading Selection from Rader's Chem4Kids.com
http://www.chem4kids.com/files/react_thermo.html
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Heat and Cold
What are heat and cold? It's a pretty simple idea. When you
think of heat, you probably think of fire. When you think of
cold, you might think of an ice cube. It all has to do with
kinetic energy in atoms. Heat has a lot of kinetic energy and
gives it away. The cold doesn't have much energy and
absorbs it from the surrounding area. Chemists measure heat
in units called Joules. You may also hear about sinks and
sources. If the temperature of an object is higher than the
surrounding area, it is considered a heat source. If the
temperature of an object is lower than the surrounding area, it
is considered a heat sink.
Thermochemistry
There are two kinds of heat in chemistry. The first is caused
by physical activity. As you get more kinetic energy, there is
more activity in the system. This extra activity makes more
molecular collisions occur. The collisions create the heat.
This happens when you increase the pressure in a system.
Chemical processes cause the second type of heat. Instead
of exciting a system and feeling the heat, chemical bonds are
made and broken, and the energy is then released. A release
of energy charges up the system and the molecules bounce
around faster, resulting in that physical activity we just
explained. The opposite can also happen. Sometimes bonds
are made and broken and energy is absorbed. The system
then gets colder as the temperature goes down. Those
emergency icepacks you see when people hurt their ankles
are good examples of chemical reactions that absorb energy.
There is energy all around us. Just as matter is all around us,
energy is always there. Usually, you will feel this energy as
heat. Let's say it's really hot out today. Why is it hot? One big
reason is that there is a lot of heat/energy coming from the
Sun. The Sun is a big furnace, and that furnace heats the
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Middle School Science with Vernier
Earth.
When a lot of the Sun's radiant
energy makes
it to
Earth, it transmits energy to the atoms and molecules in the
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air and ground. Those molecules heat up. The Sun makes
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Reading Selection from Rader's Physics4Kids.com
http://www.physics4kids.com/files/thermo_intro.html
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Heat and Thermal Energy
When scientists originally studied thermodynamics, they
were really studying heat and thermal energy. Heat can do
anything: move from one area to another, get atoms excited,
and even increase energy. Did we say energy? That's what
heat is. When you increase the heat in a system, you are
really increasing the amount of energy in the system. Now
that you understand that fact, you can see that the study of
thermodynamics is the study of the amount of energy
moving in and out of systems.
Heat of Atoms
Now all of this energy is moving around the world. You need
to remember that it all happens on a really small scale.
Energy that is transferred is at an atomic level. Atoms and
molecules are transmitting these tiny amounts of energy.
When heat moves from one area to another, it's because
millions of atoms and molecules are working together. Those
millions of pieces become the energy flow throughout the
entire planet.
Heat Movement
Heat moves from one system to another because of
differences in the temperatures of the systems. If you
have two identical systems with equal temperatures, there
will be no flow of energy. When you have two systems with
different temperatures, the energy will start to flow. Air mass
of high pressure forces large numbers of molecules into
areas of low pressure. Areas of high temperature give off
energy to areas with lower temperature. There is a constant
flow of energy throughout the universe. Heat is only one
type of that energy.
Increasing Energy and Entropy
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Another big idea in thermodynamics is the concept of energy
that changes the freedom of molecules. For example, when 6 - 13
you change the state of a system (solid, liquid, gas), the
atoms
and/or
molecules
have different arrangements and
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Absorption of Radiant Energy
LabQuest 6
http://www.physics4kids.com/files/thermo_heat.html
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Making Heat
How do you make heat? You could burn things (chemical
reactions), or you could rub things together (friction).
When you burn things, thermal energy is released. Thermal
energy is measured in calories. For example, when you
burn wood, you release 3000 calories for each gram of
wood. When you burn an apple, it creates only 600 calories.
The amount of energy released is directly related to the
chemical bonds that are broken and formed. If you use that
idea, there is more energy available when you break and
rebond the atoms in wood, than when you do the same to an
apple.
Losing Energy
We just talked about friction. Heat is also created because of
inefficiency. When a car engine runs, a lot of heat is given
off. Much of that heat is the result of the friction and
inefficiency in the running motor. When you lift something
and your muscle contracts, you are only 25% efficient.
Seventy-five percent of the energy is lost to heat.
More Transfer of Energy
Heat is the thermal energy transported from one system to
another because of a temperature difference. The transfer
of that energy stops when the temperature balances out in
the entire environment. Scientists use the unit of a calorie to
measure heat. You might be saying, "I've heard of calories.
Are those like the ones in food?" The answer is "Yes." One
calorie is measured as the amount of energy needed to
raise the temperature of one gram of water, one degree
Celsius. When you “burn” food (this happens VERY slowly in
your body), you release energy.
Specific Heat Capacity
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There is also something totally important called specific heat
capacity. It is the amount of energy required to raise the
temperature of one gram of a substance by one degree
Celsius.
The
specific
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Daylight Timeheat capacity for water is one. As we
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Absorption of Radiant Energy
LabQuest 6
http://www.physics4kids.com/files/thermo_transfer.html
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Energy Likes to Move
If there is a temperature difference in a system, heat will
naturally move from high to low temperatures. The place you
find the higher temperature is the heat source. The area
where the temperature is lower is the heat sink. When
examining systems, scientists measure a number called the
temperature gradient. The gradient is the change in
temperature divided by the distance. The units are degrees
per centimeter. If the temperature drops over a specific
distance, the gradient is a negative value. If the temperature
goes up, the gradient has a positive value. The greater the
gradient, the more energy will be exchanged.
Ever Hear of Convection Ovens?
Convection is the way heat is transferred from one area to
another when there is a "bulk movement of matter." It is the
movement of huge amounts of material, taking the heat from
one area and placing it in another. Warm air rises and cold
air replaces it. The heat has moved. It is the transfer of heat
by motion of objects. Convection occurs when an area of hot
water rises to the top of a pot and gives off energy. Another
example is warm air in the atmosphere rising and giving off
energy. They are all examples of convection. The thing to
remember is that objects change position.
Radiating Energy
When the transfer of energy happens by radiation, there is
no conductive medium (such as in space). That lack of
medium means there is no matter there for the heat to pass
through. Radiation is the energy carried by electromagnetic
waves (light). Those waves could be radio waves, infrared,
visible light, UV, or Gamma rays. Heat radiation is usually
found in the infrared sections of the EM spectrum. If the
temperature of an object doubles (in Kelvin), the thermal
radiation increases 16 times. Therefore, if it goes up four
times, it increases to 32 times the original level.
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Scientists have also discovered that objects that are good at
giving off thermal radiation are also good at absorbing the
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Absorption of Radiant Energy
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LabQuest 6
Middle School Science with Vernier
http://www.kapili.com/index_press.html
About Andrew Rader
Two of the most asked questions we receive are "Who makes
these sites?" and "Why do you make these sites?" There is one
driving force behind all of the sites created by Andrew Rader
Studios... Andrew Rader.
Andrew has a background in both science and computers. While
he graduated with a degree in Physiology and Cell Biology, he
found success working with computers in the corporate world. For
several years, he worked as a freelance designer and then moved
to Los Angeles. He found work in the entertainment industry as an
Associate Producer for an interactive television network. At that
time, the Internet was starting to grow in popularity and he began
producing small web sites. As he gained experience, he moved
on to work as Producer for auto web sites. Returning to
entertainment, he was also Senior Producer. In 2005, he returned
to developing his projects full-time.
During the time he produced commercial sites he was able to
maintain his pet projects with a small group of volunteers. The
most notable of these projects is the web site Chem4Kids.com. As
the years passed, the original chemistry site blossomed into
several companion sites. Biology4Kids, Geography4Kids,
Cosmos4Kids, and Physics4Kids eventually joined Chem4Kids.
The group also launched the math activity site NumberNut.com.
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Resources
Volz, D. L. & Sapatka, S. (2007) Middle school science with Vernier. Beaverton, OR: Vernier
Software & Technology.
http://www.geography4kids.com/files/en_solarrad.html
http://www.chem4kids.com/files/react_thermo.html
http://www.physics4kids.com/files/thermo_intro.html
http://www.physics4kids.com/files/thermo_heat.html
http://www.physics4kids.com/files/thermo_transfer.html
http://www.kapili.com/index_press.html
http://www.wisc-online.com/Objects/ViewObject.aspx?ID=sce304 An interactive describing
and illustrating the three processes of heat transfer.
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Middle School Science with Vernier