Sunrise! Time for
radiant heat!
Radiation Energy Transfer
Bring it!
012-10990 r1.04
Sunrise! Time for
radiant heat!
Radiation Energy Transfer
Bring it!
012-10754 r1.04
Radiation Energy Transfer
Introduction
Journals and Snapshots
The Snapshot button is used to capture the
screen.
The Journal is where snapshots are stored
and viewed.
The Share button is used to export
or print your journal to turn in your
work.
Each page of this lab that
contains the symbol
should be inserted into your
journal. After completing a
lab page with the snapshot
symbol, tap
(in the upper
right hand corner) to insert
the page into your journal.
Note: You may want to take a
snapshot of the first page of
this lab as a cover page for
your journal.
Radiation Energy Transfer
Lab Challenges
What is radiant heat energy?
How does radiant heat energy impact the temperature balance of the earth and
atmosphere?
Radiation Energy Transfer
Background
• The Earth receives an enormous amount of
energy from the Sun.
• Some of this energy drives processes in the
atmosphere that cause the wind and waves.
• Some of it is converted to chemical potential
energy through the process of photosynthesis.
• Some is absorbed as thermal energy by the
oceans and continents.
Radiation Energy Transfer
...Background
• All of the energy from the Sun that reaches the Earth arrives as radiant
energy, also known as solar radiation. Solar radiation is part of a large array of
energy called the electromagnetic radiation spectrum. (See diagram on next
page.)
• Our senses allow us to sense some forms of solar radiation as visible light,
ultraviolet light, and thermal energy (warmth).
• Other forms of solar radiation which we cannot see or feel include radio
waves, X-rays, and gamma rays.
Radiation Energy Transfer
...Background
Radiation Energy Transfer
Self-Check
1. Visible light is a kind of ___________ that comes in
_______ wavelengths.
a) electromagnetic radiation : short
b) energy : microscopic
c) electromagnetic radiation : medium
d) electric radio : long
e) electromagnetic radiation : long
Radiation Energy Transfer
...Background
• The process of the sun heating the earth's surface and the earth's surface in
turn re-radiating this energy is very important to many earth processes.
• Visible light from the sun passes through the atmosphere and strikes the earth.
The earth absorbs this light energy and re-emits it as infrared energy (warmth).
(See diagram on next page.)
• Earth's atmosphere is heated mainly from infrared energy re-radiated by the
earth's surface, not directly by sunlight. This is because visible light is
comprised of smaller wavelength energy that slips by atmospheric molecules,
while infrared has a longer wavelength that is more likely to strike and be
absorbed by atmospheric molecules, heating them up.
Radiation Energy Transfer
EARTH’S ENERGY BUDGET
Reflected by
atmosphere 6%
Reflected by
clouds 20%
Reflected from
earth’s surface 4%
64%
6%
Radiated to space
from clouds and
atmosphere
Incoming solar
energy 100%
Absorbed by atmosphere 16%
Absorbed by clouds 3%
Conduction and
rising air 7%
Absorbed by land and oceans 51%
Radiated
directly to
space from
earth
Radiation
absorbed by
atmosphere 15%
Carried to clouds and
atmosphere by latent
heat in water vapor 23%
Radiation Energy Transfer
Self-Check
2. Which form of electromagnetic radiation
contributes most to the natural warming of the
Earth's atmosphere?
a) visible light
b) infrared
c) x-rays
d) gamma rays
e) ultraviolet light
Radiation Energy Transfer
Safety
• Follow all standard laboratory safety procedures.
• Wear safety glasses.
• Keep water away from sensitive electronic equipment.
Radiation Energy Transfer
Materials and Equipment
Collect all of these materials before beginning the lab.
• Temperature sensors (2 separate sensors)
• Water, room temperature (0.5 L)
• Heat lamp (or 150-W lamp)
• Radiation cans (half of them painted)
• Insulated pad (2)
• Graduated cylinder, 100-mL
Radiation Energy Transfer
Sequencing Challenge
A. Attach two of the
same type of
temperature sensors
into the water filled
canisters.
B. Obtain one
unpainted (silver) can
and one painted
(black) can. Fill each
with 200 ml of water.
C. Turn on a heat
lamp that is pointed
at the two water
cans.
D. Compare the time
vs. temperature
graphs for the two
cans of water.
E. Gather data for 20
minutes as the lamp
heats the cans.
The steps to the left are part of
the procedure for this lab
activity. They are not in the
right order. Write the correct
sequence below, then take a
snapshot of this page.
Radiation Energy Transfer
Setup
1. Connect two temperature sensors to your data collection system.
2. Place each of the Radiation Cans (unpainted & black) on an insulated pad. Keep
the cans away from drafts or direct sunlight.
3. Fill each can with 200 mL of room-temperature water. Make sure the cans have
exactly the same amount of water.
Radiation Energy Transfer
Procedure
1. Put one temperature sensor into the water inside the unpainted (silver) can. Put
the other sensor into the water inside the painted (black) can.
2. Place the heat lamp so it is about 20 cm from the cans. Make sure the lamp is
the exact distance from each can, ensuring that each receives the same amount
of light radiation (radiant energy).
Radiation Energy Transfer
Procedure
Q1: What do you predict will happen? Will one of the cans heat up faster than
the other? Make a prediction below and explain your reasoning. Then take a
snapshot of the page.
Radiation Energy Transfer
Procedure
3. Start a data set collection.
4. Turn on the heat lamp.
5. Watch the dual graphs on the next page while collecting data for 20 minutes.
6. After recording for 20 minutes stop the data collection.
Radiation Energy Transfer
Radiation Energy Transfer
Data Analysis
1. Review graphs on the
previous page, then
complete adjacent data
table.
Note: see the next page for
tips on analyzing graphs and
entering data into a data
table.
Radiation Energy Transfer
*To Enter Data into a Table:
1. Tap
to open the tool
palette.
2. Tap
then tap a cell in the
data table to highlight it in
yellow.
3. Tap
to open the
keyboard screen.
*To Scale a Graph:
1. Tap
to open the tool
palette.
2. Tap
to scale the graph.
3. If you need to manually
scale the graph, touch one
of the numbers labeling an
axis and drag it up or down.
* To Find the Difference
Between Two Data Points:
1. Tap
to open the tools
palette.
2. Tap
and then tap two
points on the data run.
3. Adjust using both
buttons and then tap .
4. Tap
to display the
differences. (dx & dy)
Radiation Energy Transfer
Wrap-Up
1. Save your work.
2. Follow your teacher's instructions for cleaning up all equipment.
Radiation Energy Transfer
Analysis
1. Review your graphs and the completed data table. Which of the cans
absorbed light radiation more efficiently during the experiment? How
do you know? Use your data to support your answer.
Radiation Energy Transfer
Analysis
2. Do your data table results support or contradict the prediction you made about
the cans? Explain.
Radiation Energy Transfer
Synthesis
Use available resources to help you answer the following questions.
1. Suppose you had to choose a roof color for a new house and were given
two choices: dark grey or light grey. Which would you choose to keep your
house cooler in the summer? Why?
Radiation Energy Transfer
Synthesis
2. Which would feel hotter on a sunny summer day, the asphalt street in front
of your house or your cement driveway?
Radiation Energy Transfer
Synthesis
3. Grassy areas are typically more darkly colored than cement. Why would
they be cooler on hot sunny days?
Radiation Energy Transfer
Multiple Choice
1. If the same amount of solar radiation has been
hitting the earth for most of the planet's history,
why has the atmosphere been warming up over
the past 200 years?
a) The earth’s color has been getting darker.
b) Global warming has dried out the ground
making it absorb more radiation.
c) Since earth is not gaining more energy from
radiation it must not be able to lose as much
energy as before.
d) The warmer atmosphere creates more methane
clouds which absorb more radiation than when
there were less clouds.
Radiation Energy Transfer
Multiple Choice
2. Why does incoming visible light pass easily through
the atmosphere while outgoing infrared radiation is
more likely to be absorbed by the atmosphere?
a) Infrared radiation has a shorter wavelength so it
gets reflected by dust and particles in the air.
b) Visible light must make it through the
atmosphere otherwise how would we be able to
see anything.
c) Molecules in the air are highly able to absorb
visible light making the atmosphere opaque.
d) Visible light has a wavelength that passes by air
molecules while infrared has a longer
wavelength more likely to hit air molecules.
Radiation Energy Transfer
Congratulations!
You have completed the lab.
Please remember to follow your teacher's instructions for cleaning-up and submitting
your lab.
Radiation Energy Transfer
References
Images are taken from PASCO documentation, public domain clip art, or Wikimedia Foundation Commons.
ROCK ARCH PHOTO. Copyright Matt Fishbach 2008, licensed to Pasco Scientific.
http://www.freeclipartnow.com/office/paper-shredder.jpg.html
http://commons.wikimedia.org/wiki/File:EM_Spectrum3-new.jpg
http://commons.wikimedia.org/wiki/File:NASA_earth_energy_budget.gif
http://en.wikipedia.org/wiki/File:The_Earth_seen_from_Apollo_17.jpg'
http://www.freeclipartnow.com/nature/weather/sun/decorative-sun.jpg.html