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Mysteries of the Deep
  Teaching Guide
Activity 2: Grades 5-8
Leaky Seal

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  1. What was the role of the ring of rubber material?
    (It acted as a gasket to produce a waterproof seal between the adjoining metal surfaces)
  2. Although the lids were metal, both setups were very buoyant. Explain.
    (The paired lids trapped a volume of air that produced sufficient buoyancy to float each system)
  3. What was the role of the fishing sinkers?
    (Their added weight was needed to keep the lids at the bottom of the water-filled tank)
  4. Predict the buoyancy of each lid system over time.
    (The system that lacked the gasket would be first to fill with water. Therefore, it would sink first. Although the gasket fitted system would resist water, eventually, the rubber bands or gasket itself would fail, allowing water to spill inside the system resulting in a loss of buoyancy.)

The activities in this guide were contributed by Michael DiSpezio, a Massachusetts-based science writer and author of "Critical Thinking Puzzles" and "Awesome Experiments in Light & Sound" (Sterling Publishing Co., NY).

Academic Advisors for this Guide:
Corrine Lowen, Science Department, Wayland Public Schools, Wayland, MA
Suzanne Panico, Science Teacher Mentor, Cambridge Public Schools, Cambridge, MA
Anne E. Jones, Science Department, Wayland Middle School, Wayland, MA
Gary Pinkall, Middle School Science Teacher, Great Bend Public Schools, Great Bend, KS

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