PURPOSE: To show the density of water.
DESCRIPTION: A neutral bouyant sphere is placed into a beaker of warm water. A thermocouple displays the temperature of the water. With the water at about 120 degrees the sphere sinks on the bottom. A fan is used to blow cool air at the beaker to cool the water. At about 100 degrees the water is cool enough and dense enough for the sphere to rise and float.
EQUIPMENT: Neutral bouyant sphere, 1000 ml beaker with warm tap water, fan, thermocouple as photographed.
Updated by Jun Qi in 4/5/2000