 The sun gives us a lot of energy in the form of heat. At the equator, the earth receives about one kilowatt of energy on every square meter. A kilowatt is 1000 watts, or the amount of energy needed to light ten 100-watt lightbulbs. If we could make use of this energy, it would reduce pollution and our reliance on fossil fuels. You can easily see how to collect solar energy as heat by doing a simple experiment. You will need two large empty pop bottles, two balloons, and some white and black acrylic paint. Paint both bottles, one white and one black. Then attach a balloon tightly to the top of each bottle, as shown below.   Place both bottles outside where they are exposed to sunlight. It won't take very long for the balloon on the black bottle to start to expand. The balloon on the white bottle will hardly change.
Here are some questions that you should think about:
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