Review the meanings of the words, mass, volume, and density, since they
are important in this activity.
One three liter soda bottle, with label removed.
One glass dropper.
One beaker, deeper than the length of the dropper.
A waterproof marker
1. Place marks, more or less evenly along the
tube of the dropper. (fig. 1)
2. Put water in the beaker until nearly
3. Fill the dropper about half full with
4. Place the dropper in the beaker.
5. If the dropper sinks, take a drop of water
If the dropper floats
too high, add a drop of water.
6. Repeat steps 4 and 5 until the dropper
just barely floats. (fig. 2)
7. Fill the soda bottle with water.
8. Place the dropper into the bottle without
9. Put the cap on the bottle.
10. Squeeze the bottle gently, the diver should go
the bottom of the
11. Release the bottle, and the diver should go to
12. Observe carefully as the diver goes up and down.
What changes do
13. How do these changes effect the average density
of the dropper and the air and water it contains?
14. Does the hardness of your squeeze have any
effect on the diver?
15. Can you squeeze and hold just enough that the
diver stops in the middle of the bottle?
16. Empty the bottle, clean up your lab station, and
return to your seat.