How do water rockets work?

Shoot for the moon. Even if you miss it, you will land among the stars!

how do water rockets work?

contents

what happens when you launch water rockets?

science behind water rockets

launcher

how is a water rocket built?

Back

fins: 3 or 4 triangels made of cardboard

body: 1.5- or 2-littre plastic bottle (upside down)

nose cone: a bottom part of a plastic bottle

water bottle rocket

Back

launcher

Back

1. You fill in 1/3 of your rocket with water.
2. You pump your rocket with the air (up to 100 psi).
3. The pressured air tends to lower its pressure (which means, it tends to make its volume bigger) so it pushes the water out of the bottle.
4. As a results, when the water (which has quite high density) is pushed out, it creates the force of opposite direction (the water goes down so the force is directed up).

launching water rockets

Back

the point where the mass of an object is evenly distributed

centre of mass

Back

an object would rotate around its centre of gravity as the acrobact on the platform does; it means the weight of the acrobat and the platform (as a counter balance) are equal

the point at which the distribution of weight is equal in all directions

centre of gravity

Back

TIP

to ensure the rocket stability, the centre of pressure should be under the centre of mass (or the centre of gravity)

the point where aerodynamic forces (lift, thrust, drag and weight) are equally distributed

centre of pressure

Back

As the water and air shoot out of the bottom of the bottle (action), the rocket is thrust upward (reaction).

For every action there is an equal and opposite reaction.

newton's 3rd law of motion

THANKS!