PURPOSE: To demonstrate a fluid whose viscosity increases dramatically when a large force is applied.

DESCRIPTION: Mix cornstarch and water to the consistency of heavy syrup. Dipping your hand into the mixture and raising it, the goo drains off your hand rather rapidly, with a reasonably low viscosity. When your hand is slapped down onto the surface of the mixture, its viscosity increases dramatically and it will not splash! Check that the consistency is correct by tapping the surface with one finger.

SUGGESTIONS: Fluid must be used shortly after mixing so that it will not become too dry. Mix well before slapping.


EQUIPMENT: Cornstarch and water in cake pan, with mixing spoon.

SETUP TIME: 5 min.

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