Purpose:Demonstrate the change in the density of water with temperature.
Description:A calibrated thin spherical metal shell with air and shot inside sinks in water at 115 degrees F. The water is then cooled by a fan, whereupon the sphere rises to the top of the water when a temperature of about 110 degrees F is reached. The water can be stirred continually to keep the temperature uniform using the digital thermometer probe, which simultaneously reads the temperature, which is displayed on a large scale. If the sphere starts out floating and is sunk by heating the water, the demonstration requires more time due to surface tension.