MS-157 PVG DENSITY BALL

 DENSITY BALL

To demonstrate the effect of Temperature on Density of Liquids.

As the temperature is raised the density decreases. In cooler (i.e., more dense) water, the Density ball floats; in hot water  means less dense, water, the ball sinks.

Archimedes’ Principle says  an object displaces a volume of fluid with a weight equal to its own. The mass of the PVG’s density ball is fixed, so when the water is cold and more dense the ball needs to displace less water in order to float. As the water temperature is raised and its density drops, the ball displaces a larger volume of water to remain floating. When the volume of water required exceeds the volume of the ball, the ball sinks.

The simplest way to do this demonstration to students is to start with the ball floating in a beaker cap.1000 ml , of cool water. Then slowly add hot water from the kettle or heat the beaker, monitoring the temperature, until the ball sinks. When the water cools enough Density ball start floating again.