Practise and challenge your friends! Download the Water bottle Rockets PDF(378 Kb). Adobe Acrobat is required. SAFETY: This rocket uses air pressure to fling a bottle at high speed 20–50 metres.

Water exerts the pressure caused by its own weight and that of the air above it ... and so in all regular figures. In a bottle having a long narrow neck, the pressure is greatest on the base ...

This also means that the pressure is lower. This is why the balloon in the freezer shrank. At higher altitudes the weight of the air particles ... the bottle. The Arrows show how the water ...

The bottle is a closed system, and the only way to increase its pressure is to squeeze it into a smaller shape, or else add ...