In a hot country like Sudan a family loses up to half their tomatoes, okra and carrot crop as they deteriorate rapidly in the heat. Practical Action has developed a clay pot (zeer pot) refrigerator. A smaller pot is placed inside a larger one with the gap filled with damp sand. A lid is placed on top and the outer pot placed in a metal stand to raise it off the ground. As the moisture in the sand evaporates the pot is cooled keeping the contents fresh for longer.
Children will carry out a fair test to compare how long it takes an ice cube to melt when contained in their own mini 'cool pot ' with how long it takes in a single pot.
Children will be able to work scientifically by:
- setting up simple comparative/fair tests
- reporting on findings from enquiries, including oral and written presentations, displays or presentations of results and conclusions.
Children will learn:
- that some materials change state when they are heated and cooled
These resources were initially developed in partnership with Practical Action.