Cooking with the Sun

(Adapted from NASA.gov)

Could Humans Live of the Moon?

Use the following link to watch the video “Living on the Moon”

(It is the second video on the page)

If we were to establish a habitat on the moon for research, we would have to bring just about everything we needed with us. The moon has no atmosphere, no weather or climate, and very little resources. All of the things the moon lacks, actually make it the ideal place to collect and use solar energy. The sun will not be blocked by clouds, or scattered by the atmosphere! The only time that the sun wouldn’t be out during a lunar day would be during rare lunar eclipses. If we were able to capture even a small portion of this sunlight, we could use it to power our entire habitat, including that very important device that allows us to cook our food-an oven!!!!

Pre-lab Questions

  1. The moon is not the only place that a solar cooker could come in handy. Describe two situations in which a solar cooker would be useful here on Earth.
  2. What are the 3 mechanisms of heat transfer that we learned about in class? Make sure to define each one.
  3. Explain the role that each mechanism of heat transfer will play in our solar cookers.
  4. What are 3 things that can happen to radiation when it strikes an object? Which do you think is most important in solar cooking?

The Challenge

Your mission is to design and build a solar oven to cook your own S’mores using cardboard and other simple materials.

Rules:

-It must have a footprint no larger than 40 cm x 40 cm

-It must use one of the Plexiglass sheets provided

-Your food may not touch the oven directly

-You must be able to cook 2 marshmallows at once at two different heights

-You may use any available materials and designs as long as these rules are followed

-Everybody must cook with a 100W lamp at the same distance from the solar cooker.

Background Information

To help you get started, look at this graph and answer the questions below.

Title: The temperature change of 3 solar cookers in 15 minutes

  1. Which line do you think represents the empty box? Why?
  2. Which line do you think represents the box with a black bottom and aluminum foil? Why?
  3. What is the purpose of the black bottom? (Think of your answer to question 4 in the pre-lab)
  4. What is the purpose of the aluminum foil? (Think of your answer to question 4 in the pre-lab)

The Design

  1. Draw a diagram of your design. In your diagram make sure that all materials are labeled, and make sure that you show how you will make your marshmallows not touch the box. Remember that you will need to cook 2 marshmallows at once
  2. Do you think that the height from the bottom of the box will affect the rate that your food cooks? Explain.

Recording your Results

You will be conducting 2 experiments at once, so it is important to have clear and organized data tables prepared before your start. For the first experiment you will be measuring the temperature change inside your box each minute for 10 minutes. Below your answer to question number 10, create a “Results” section. It is in this section that you will create your data tables. Label the first one, Data Table 1 and give it a detailed title. This table will be where you record temperature change each minute. Make sure to think about your data table first. It must look organized!

The second experiment that you will be conducting is how the height above the bottom of the solar cooker affects the rate at which food cooks. You may choose any two heights you would like to test, but make sure to record your measurements. Label your next table, Data Table 2 and give it a title as well. In this table you will record observations about each marshmallow. You should record your observations every 2 minutes. These will just be descriptions on what you see, smell, etc. Again, make sure to plan out a data table that neatly displays your information.

The Experiment

Once your data tables are constructed you are ready to begin! Set up your lamp at the agreed upon height, put your marshmallows and thermometer in place, and turn on the lamp! Good Luck, and observe carefully as things will get hot!

Discussion Questions

  1. Draw your solar oven in action. This time you do not need to label the parts. Use 3 different colors to label conduction, convection, and radiation where you think each is happening.
  2. Which heat transfer method do you think is least useful in solar cooking?
  3. What are quantitative observations? In which data table did you record them?
  4. What are qualitative observations? In which data table did you record them?
  5. Create a graph of Data Table 1 that shows how the temperature in your oven changed over time. Make sure it has the 5 things all graphs need!
  6. What 2 heights did you test? Did the height affect the results? Explain.
  7. What were the strengths of your design?
  8. What were the weaknesses of your design?
  9. What would you change about your design next time?
  10. Solar ovens are a great way for impoverished people in developing nations to cook food. If you were going to donate your solar oven to somebody, where in the world would it be the most effective? Where would it make least effective? Use the map below to justify your answer.