Radiation Energy Transfer Sunrise! Time for radiant heat! Bring it! 012-10990 r1.04.

Radiation Energy Transfer

Sunrise! Time for radiant heat!

Bring it!

012-10990 r1.04

Radiation Energy Transfer

Sunrise! Time for radiant heat!

Bring it!

012-10754 r1.04

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.

IntroductionJournals and Snapshots

Note: You may want to take asnapshot of the first page ofthis lab as a cover page for your journal.

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.

Radiation Energy Transfer

Lab ChallengesWhat 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

...BackgroundRadiation Energy Transfer

Self-Check1. 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

Radiation Energy TransferEARTH’S ENERGY BUDGET

Incoming solar energy 100%

Reflected by atmosphere 6%

Reflected by clouds 20%

Reflected from earth’s surface 4%

Radiated to space from clouds and atmosphere

64%

Radiated directly to space from earth

6%

Radiation absorbed by atmosphere 15%

Carried to clouds and atmosphere by latent heat in water vapor 23%

Conduction and rising air 7%

Absorbed by clouds 3%

Absorbed by atmosphere 16%

Absorbed by land and oceans 51%

Self-Check2. 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 EquipmentCollect 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

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.

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.

Sequencing ChallengeRadiation Energy Transfer

Setup1. 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

Procedure1. 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

ProcedureQ1: 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

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.

ProcedureRadiation Energy Transfer

Radiation Energy Transfer

Note: see the next page for tips on analyzing graphs and entering data into a data table.

Data Analysis1. Review graphs on the

previous page, then complete adjacent data table.

Radiation Energy Transfer

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)

Wrap-Up 1. Save your work.

2. Follow your teacher's instructions for cleaning up all equipment.

Radiation Energy Transfer

Analysis1. 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

Analysis2. Do your data table results support or contradict the prediction you made about

the cans? Explain.

Radiation Energy Transfer

SynthesisUse 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

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

Synthesis

Multiple Choice1. 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 Choice2. 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

You have completed the lab.Congratulations!

Please remember to follow your teacher's instructions for cleaning-up and submitting your lab.

Radiation Energy Transfer

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.htmlhttp://commons.wikimedia.org/wiki/File:EM_Spectrum3-new.jpg http://commons.wikimedia.org/wiki/File:NASA_earth_energy_budget.gifhttp://en.wikipedia.org/wiki/File:The_Earth_seen_from_Apollo_17.jpg'http://www.freeclipartnow.com/nature/weather/sun/decorative-sun.jpg.html

ReferencesRadiation Energy Transfer