Water Rocket

Use the  Water rockets booklet. The booklet will have the 

answers for many of your questions.

Aerodynamics

Aim: To investigate the best design features for your water rocket.

Read page 20 of the booklet.

Section 1: What is a water Rocket

Its Simple, a water rocket is basically an upside down fizzy drink, Bottle which has had a 'Nose' cone and some fins added. 

The nose cone

The job of the nose cone is to make the rather snub-nosed end of the fizzy drink bottle more aerodynamic also if you have 'payload' on your rocket or a parachute mechanism this is probably where it will be placed.

the Fins

Others might disagree but i think the fins are the parts of a rocket that really give a rocket its character technically, the fins are important for ensuring that the rocket flies smoothly

Once we have added the fins and the nose cone, we have something which looks like a rocket. But how do we make it go like a rocket? 

First we need to add some water, and some kind of release mechanism, that will keep the water in the bottle, until we choose to release it. The water will then leave the bottle through its nozzle. 

Typically the bottle will be between about one quarter and one third filled with water. 

Launch

 To launch the water rocket, we need to pump air into the rocket: this provides the energy for the launch. As the air enters, it bubbles up through the water and pressurises the ‘empty’ space above the water. You can see that the release mechanism has to be really quite clever, allowing air into the rocket, while not allowing the water to escape until we activate a trigger.