Discuss the museum activities with students
1 - Measuring Waves
What were student results for wavelength, frequency and speed?
What relationships do these results have with each other?
(You will need to compare different groups' results to answer some of the following questions.)
Ask students to finish this statement:
"The longer the wavelength, the [blank] the frequency."
How did students measure the waves? Share strategies. Did the technique affect the results? Why is it important for scientists to share the methods of gathering data, as well as the data themselves?
What other statements can students make about their data?
Which wavelengths seem to have the most energy?
What is wavelength?
2 - The wavelengths of light
Which light bulb setting: mercury, sodium, or incandescent did students choose as most similar to the sun? Why did you choose that light bulb?
The incandescent is closest to sunlight.
Ask students to describe what colors they noticed as the exhibit graphed the light.
Where did these colors come from?
The prism in the exhibit refracted (bent) the white light so that all colors that make up the white light could be seen.
What happened when the light energy was blocked with the clipboard?
No colors were seen, and the graph shows no energy
Describe what happened when the filters were used to filter the light energy.
Certain colors would not appear when the light is blocked with a certain filter. No colors are seen when all filters are used together. The filters do not block the infrared energy, even though no visible light was noticed.
What kind of light energy was present even though no visible light was apparent?
Infrared
Summarize and discuss: Can we see all types of light energy? Is it possible for the solar car to capture some energy when it is cloudy and dark?
3 - Angles of Sunlight
Look at your data.
Is there any energy available on a cloudy day? What evidence do you have?
How did students answer the questions at the bottom of the page? (use conversion from fractions to percents and then compare with results)
Make a graph with one axis being the angle of the solar cell ("sunlight") and the other axis as the amount of solar energy. Use the graph to predict what the energy amount would be for an angle of 25° ; 75° .
What effect does the angle of the sun with the solar panel have on the amount of energy captured?
How would you use this information in designing a solar car?
4 - Time to Drive?
How does the tilt of the earth affect the shape of light and the seasons?
Does the sun really provide less energy in the winter than the summer?
No, the amount of energy the sun provides is the same all the time.
What did change?
The angle the light is hitting the earth, or more accurately the earth's atmosphere. In the winter the light passes through more atmosphere because the earth's tilt is away from the sun producing a smaller angle between the sun's rays and the earth. The atmosphere absorbs and scatters more of the light energy.
What evidence is there that less of the sun's energy reaches us in the winter? (Hint: light energy can become heat energy)
Check out the solar energy and buildings activity for more evidence.
Solar energy and buildings
We can use the sun to provide energy for buildings. The Science House at the Science Museum of Minnesota has solar panels on its roof to supply electrical energy to the building. It uses the same technology as the solar car but uses the electricity to power lights and machines rather than a car. Use the Science House PDF to calculate the amount of average energy the House generates at different times of the year.
Check your answers on the Science House website
John Carmody is an architect who helps design sustainable buildings. He uses his knowledge of light energy to heat buildings, keep them bright, and provide electricity.
Watch the interview with John Carmody to learn more about the sun's energy and architecture.
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