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Physics/finding volume of a cardboard boat


hi, i am a h.s. physics teacher and i have students build cardboard boats for a unit in liquids. i am wondering how we can find the volume of these boats that hold two people after they are built.  I make the students float them and run a water course.  without breaking down the boats into different shapes and finding the volumes of the different shapes and adding them together(which I dont really want to do) i dont know how to do it.  thanks for your time


Interesting that it's a unit on liquids.  Can you displace enough liquid to almost sink the boats, or will it ruin them?  Can you fill them with liquid and measure the volume of that?  Can you fill the boats with a big bag and fill the bag with some regular source, like a pump, and then measure the volume per pump?  Perhaps you can figure out the volume of a gallon of packing peanuts and fill the boats with styrofoam peanuts, then convert?  That's probably the easiest could cut out the very bottom of an empty gallon water/milk jug and use it as a scoop with minimal volume loss.

If any direct measurements fail, perhaps you can take measurements.  If the shapes are regular, it's pretty easy to figure out the area of the side and multiply by the width.  The more complex the shape, the more little pieces of volume you'll have to use to do this method.  I'd stick to styrofoam peanuts if you can.


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Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

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