Materials
included in the Floating and Sinking unit kit.
In this unit, students investigate the phenomenon of buoyancy. They
begin by making a spring scale with which they weigh various objects. They make clay
boats, test their boats’ buoyancy, and discover that altering the shape of the boats
affects buoyancy. Students are then challenged to design a boat that has a certain loading
capacity. These experiments allow them to witness several surprising phenomena; for
example, some “floaters” are heavier than some “sinkers,” and large
objects are not always heavier than smaller objects. Students then turn their attention to
differences between objects placed in fresh water and in salt water. They construct a
hydrometer that compares the levels at which objects float in both types of water.
