Nine Squares

Wood and Metal rod

Boiling wter in a paper cup

Relevant Resource Questions

Concepts demonstrated :

• heat
• energy transfer
• conduction

Equipment needed :

• heat pipes
• CCD camera

Accessories (ie posters etc) :

None

Physics involved :

Heat pipes can transfer large amounts of power with very small temperature differences. The effective thermal conductivity of a heat pipe can be more than 100 times that of copper.

Heat transport is achieved by vaporisation, transport and condensation of a working fluid within the low pressure heat pipe. The condensed working fluid is returned to the evaporator as a liquid, enabling the process to continue indefinitely.

How to use the Demonstration :

• Ask the students what materials they believe conduct heat the most rapidly.
• Show them the heat pipes and get some students to examine them closely.
• Ask the students to explain why the pipe with water in it under a reduced pressure is a better conductor of heat.

• steam from a kettle when it starts to boil

Other Comments :

• Due to its physical size this demonstration is not very protable.