Ball and ring

Back to 4A - Thermal properties of matter
PIRA index: 4A30.20

Description

A metal ball has a diameter barely small enough to go through a ring at room temperature. When heated, the ball is too big to fit in the ring. One version of this demo has the ball resting on the ring and will eventually go through when its temperature is low enough.

Equipment

• A matching ball and ring set

Instructions

With all the objects at room temperature, show that the ball can go through the ring. Heat the ball. Show that ball is unable to go through the same hole. One version of this demo allows you to leave the ball on the ring (while you continue with the lecture), it will take a few minute to cool down enough to let the ball through.

Keywords

ring, ball, thermal expansion, temperature.