A balloon is simple example of a rocket.

Rubber walls compress the air inside.Air escapes from the opening at one end and the balloon flies

Awater rocketis a type ofmodel rocketusingwateras itsreaction mass.

The engine of the rocket is usually a used a plasticbottle, the water is forced out by a pressurized gas, orcompressed air.

Newtons 1st law: Object at rest will remain at rest, and object in motion will remain in motion in a straight line unless acted upon by an unbalanced force

Newtons 2nd law: Force equals to mass times acceleration

Newtons 3rd law: Every action has an equal and opposite reaction

At rest: Forces are balaced. The force of gravity on the rocket balances with that of the launching pad holding it up

In motion: Thrust from the rocket unbalances the forces. As a result, the rocket travels upward

thrustgravity

The pressure created inside the rocket acts across the area of the bottles throat and produces force (thrust)

Mass represents the total mass of the rocket (including its fuel)

The mass of the rocket changes during flight. As a fuel is rapidly used and expelled, the rocket weighs less and accelerates

A rocket takes off only when it expels water.

The thrust has to be greater than the weight of the rocket for the liftoff to happen Action: The rocket pushes the water outReaction: The water pushes up on the rocket

Trajectory : Curved path of an object travelling through spaceFactors that affect bottle trajectory:Flow rate of fuel existing (Bottle internal pressure, Air volume and densities)Mass of bottleAir resistance (Bottle aerodynamics)

Design a parachute from a plastic bag