Tea bag experiment

This morning in maths we started of with an experiment, that involved a tea bag and a lighter

The tea bag is like a hot air balloon when Mrs stone sets the teabag on fire the air inside of the teabag starts to heat up and because it is heating up it is starting to rise because heat always rises it pushes against the fabric wall of the teabag and forces the tea bag to rise into the air.Hot air rises because it has more energy than cold air