The Effect of Fruits on Generating Electricity By Payton Rockwood Robert Louis Stevenson Middle School 6th Grade 7th period

Introduction Background Info: A potato battery is an electrochemical battery. This battery takes chemical energy and turns it into electrical energy. In this experiment, I will compare a potato to other fruits. Question: Which fruit or vegetable generates the most electricity? Hypothesis: I think that the grapefruit will generate the most electricity because it is the most acidic. Experimental Variables: grapefruit, potato, coconut, and pineapple Constant Variables: copper wire, pennies, voltmeter, and galvanized nails

Materials 1 grapefruit 1 coconut 1 potato 1 pineapple 4 galvanized steel nails Copper wire 4 shiny pennies Voltmeter

Procedure Gather materials Cut a slit with a knife for the penny in the potato Wrap a piece of copper wire around the nail Do the same for the penny Insert the nail and penny into the potato on opposite sides and make sure they don’t touch Take the black (positive) probe on the voltmeter and touch it to the wire around the penny. At the same time, take the red (negative) probe on the voltmeter and touch it to the wire around the nail Record what you see on the voltmeter Repeat procedure for the pineapple, coconut, and grapefruit

Observations & Data Trial 1 Trial2 Trial 3 Grapefruit 135 mA 134 mA mA=milliamps Trial 1 Trial2 Trial 3 Grapefruit 135 mA 134 mA 141 mA Potato mA 46 mA 48 mA Coconut 120 mA 105 mA 90 mA Pineapple 42 mA 39 mA 44 mA

Data Analysis In my experiment, the grapefruit generated the most electricity. The pineapple was the worst, then the potato, then the coconut, and the grapefruit was the best. A few trends that I noticed are that the farther I pushed the penny into the fruit, the more electricity it made and also the more copper that you wrapped around the penny, the more electricity it made. Another thing that could change my data on the coconut is that I was only able to get a piece of wire into it instead of the whole penny.

Conclusion My hypothesis was correct and the grapefruit generated the most electricity because it was the juiciest and the most acidic. However, the coconut could have very likely generated the most electricity considering the factors. Some unexpected factors that could have affected my experiment are that if the penny was shinier the first time than in the second or if the fruit wasn’t good. If I did my experiment again I would figure out a better way to get the penny into the coconut. My recommendations on this experiment are to clean the penny and nail before you put it in your different fruits and vegetables.

Works-Cited & Acknowledgements "Potato Battery | Clock | Science Fair Project | Energy | Chemical | Electrochemical." Website For Kids | Kids & Teen Chat Room | Free Kids Games | Contests | Safe Website For Kids - Kidzworld. N.p., n.d. Web. 18 Apr. 2010. <http://www.kidzworld.com/article/4726-how-potato-batteries-work>. I’d like to thank my mom and dad for helping me with the experiment and Mr. Pham for being a cool teacher. Thanks!