Product Overview
A simple and economical device to introduce students to the concepts of expansion and contraction of metals. It consists of brass and PP balls 15 mm in diameter individually mounted on rods with chains, and a steel ring mounted on a plastic rod. Both brass and PP balls pass easily through the ring when at room temperature. If the PP ball is held in boiling water, and the brass ball held in flame of alcohol burner, and then brought up to the ring, neither ball will pass through. However, if the brass and PP balls both are heated in boiling water, the brass ball will pass through the ring while the PP ball will not. When cooled, both balls pass freely through the ring again. These experiments demonstrate the expansion and contraction of solids.
Important: Never attempt to heat the PP ball or the steel ring mounted in plastic handle in flame of the burner as this will melt the plastic and may cause a fire!
