Science Buddies: "Ask an Expert"

We have purchased the veggie power experiment kit & have printed the instructions. The abstract indicates 6 - 10 days to complete the experiment. What is included in this duration ~ research, running the procedure, documenting results, preparing the display? Do you have to leave the electrodes in the potatoes until you get a reading of 2 or higher? The instructions say to adjust the setting on the multimeter if your initial reading is below 2. We are unclear on if there is wait time in the procedure or if you simply take the reading and move on to the next battery configuration.

Thanks!
Gabe & Dan Roof

Hi Gabe and Dan,

The 6 to 10 days includes time for gathering materials, setting up the experiment, collecting data, and analyzing it. The experiment itself need not last for 6 days. You do not need to leave the electrodes in the potatoes for that long. You can take the reading once it has stabilized and then move on to the next part of the project.

Post back if you have other questions.

Hi Gabe & Dan,

Sorry for the confusion on this. For many of our projects that include "specialty materials" (stuff you have to order online and can't just find laying around the house), the "Time Required" includes an estimate for shipping (and, as Terik mentioned, other things like doing your background research and making a poster etc - not just the experiment itself). Since some kids tend to wait until right before a project is due, that helps give parents a better idea of how long the ENTIRE process will take. So, you don't want to start a 6-10 day project the night before it's due. Unless the Procedure section of a project explicitly says "Now wait 3 days before you take your reading", you shouldn't need to worry about waiting for long periods of time during the experiment.

I've clarified the wording on the Veggie Power page to indicate that "Time Required" includes shipping. I hope the project goes well!

-Ben

I'm doing the experiment with 3 potatoes connected in series and then soaking them in water and repeating the experiment. All the data indicates less electrical output but I'm not sure the why? Guessing is because the electrolites are diluted. Is this rt?.Where can I find more info for my conclusion. Thanks Mrs. C

ultragisel - In quickly reading the procedure I did not find a reference to soaking the potatoes in water between readings. Should there be excess water on the exterior of the potato, sufficient surface electrolyte may create a leakage path and current flow may tend to exhibit a partial 'short circuit' across the electrodes causing a lower voltage and current reading. Just my speculation.

Rick Marz