This afternoon, in our science lesson, we took to the field to carry out some experiments with bottle rockets. The rockets were made from plastic fizzy-drink bottles, with a cork instead of a lid. Into the cork, we inserted a football pump valve. In our first experiment, the rockets were 1/4 filled with water, then air was pumped into them through the valve until they took off. We measured the horizontal distance that they travelled.
In our second experiment, we kept the volume of water the same (300ml) each time. We discussed the forces acting on the bottles to make them move, slow down and fall.