Solar Water Heater
For this project, we had to design and build a solar water heater. As you can see in the picture, my group designed a heater that had two bottles connected to plastic tubing. This plastic tubing was then connected to copper tubing. The copper tubing ran through a box covered in aluminum foil to reflect as much light as possible on the copper tubing. We also angled the box so that (based on our location and time of day and year) it could get the most vertical light. To test our water heater, we set it outside facing the sun and ran 200 mL of water through. Once the water reached the bottom bottle, we poured it back into the top bottle. We continued to run it through like this for 30 minutes. We ended up with 50 mL of water and a 5 degree temperature change(we started at 13 degrees C and ended at 18 degrees C). Unfortunately, our water heater didn't work as well as the other groups. We lost a lot of water because we had too many connection points. If I were to build another water heater, I would have the water sit in the tube for the entire time.
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For this lab, we designed wind turbine blades for VAWT and HAWT at low, medium, and high wind speeds. After making many designs, we found that for the lower wind speeds, lighter designs generated more energy than heavier ones. We tested four different designs. First, we had a bowl design which was heavy. It got 0.09 volts on low and 0.11 volts on medium. Our next design was shaped more like a hat. It was also a heavy design. It got 0.07 volts on low and 0.09 volts on medium. Then, we tried a lighter design. It had square shaped blades. It got 0.38 volts on low and 0.48 volts on medium. After, we tried the same blades at a different angles and got similar results. We decided that the bowl and hat designs were heavier so they spun much slower than the light saran wrap blades. They spun 0.33 volts faster on average. This is due to the impact of mass to force in the F=ma equation. If mass increases, acceleration must decrease to balance the equation. Therefore, a lighter design will produce more energy.
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