Relevant Resource questions :

Concepts demonstrated :

• Thermal expansion and contraction

Equipment needed :

• Rubber Band Wheel
• hot air gun

• Mount rubberband wheel and point hot air gun at one section of the rubber bands. Be careful not to heat the rubber bands too much as they will melt.

None.

Physics involved :

Heating the rubber band causes it to contract. There is a shift in the centre of mass of the rubber band, relative to the axis of rotation, causing the wheel to fall (rotate).

How to use the demonstration :

• Discuss the concept of thermal expansion and contraction with the students.
• Perform the demonstration.
• Ask students to explain why the wheel rotates.

Things to do or add :

Other Comments :

• Not a very successful demonstration. It is quite difficult to get the wheel balanced so that during the heating process the rotation of the wheel stops and starts.
• Redesign the demonstration, perhaps with the "waterbird" idea.