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Museum of Science
Museum of Science and Industry: Online Science: Design a Submarine
Become an engineer, and design a submarine that moves in the water like a real submarine. Try making it sink, float, and hover in the water.
Center of Science and Industry
Cosi Columbus: Buoyant Bubble [Pdf]
Learn about density in this hands-on science experiment. Includes full list of materials, procedures, and scientific explanation of what makes an object float or sink. [PDF]