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Buoyancy - Boat And Rock
Purpose
To illustrate buoyancy in a perhaps counterintuitive manner.
Equipment
Fish tank with plastic "boat" and lead "rock."
Suggestions
Ask your students to vote on the outcome before doing the experiment.
Setup Time
5 min.
Images
Description
You and a large rock float in a boat on a closed pond. Q: If you throw the rock out of the boat and it sinks to the bottom of the pond, does the water level in the pond (a) go up, (b) go down, or (c) remain the same? A: The water level in the pond will go down when the rock sinks in the pond.
References
C. Frank Griffin and Peter N. Henriksen, Physics challenges, TPT 18, 135-136 (1980).
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See pagesf1. pressure in static fluids
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See pagesf2. buoyancy
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See pagesf3. surface tension
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See pagesf4. fluid in motion
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See pagesf5. pressure in moving fluids
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See pagesf1. pressure in static fluids
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See pagesf2. buoyancy
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See pagesf3. surface tension
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See pagesf4. fluid in motion
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See pagesf5. pressure in moving fluids
Physics Lab Demos