10
Part II
Interactive Demonstration
(The author is grateful to Dr. Michael Loverude for contributing this Activity.)- A. A glass bottle is partly filled with small pieces of metal and sealed so
that no air or water can enter or leave the bottle. The bottle is
placed in a container of water and is observed to float as shown in
the figure to the right.
Imagine that several pieces of metal are removed, and the bottle is
placed beneath the surface of the water in the container and released.
Predict the resulting position of the bottle by drawing a sketch in the
space below. Explain your reasoning.B. Your instructor will now perform the demonstration. Was your prediction confirmed? If there is
a difference between the observed results and your prediction, reconsider your explanation!C. (i) If you consider the bottle and its contents as a unit, what can you say about the
density of this unit? Explain.(ii) How is the density of this unit related to the behavior of the bottle? Explain.- Now the pieces of metal in the bottle are adjusted so that when the bottle is again
placed in a container of water, it is observed to BARELY float, as shown.A. If you consider the bottle and its contents as a unit, what can you say about
the density of this unit? Explain.B. Imagine that one more small piece of metal is added and the bottle is placed beneath the surface
of the water in the container and released. Predict the resulting position of the bottle by drawing a
sketch in the space below. Explain your reasoning.C. Your instructor will now perform the demonstration. Was your prediction confirmed? If there is
a difference between the observed results and your prediction, reconsider your explanation?