Summary

As from the Newtons Law, all objects in state of uniform motion will remain unchanged unless theres external force. A rest body is considered to have zero speed. If an unbalanced force acts on an object, that object will accelerate or decelerate in the direction of the force. It can be represented by a formula F = ma. For every action force, there is an equal and opposite reaction force and this is what make the rocket moves upwards.

It is known that at static situation, the net force is balanced. The force of gravity and the support force from the launch pad are balanced. When in dynamic motion, thrust from the rocket unbalance the force. In results, the action force is greater than the force of gravity, hence, the opposite direction and equal reaction force is applied on the rocket, which push the rocket moves upwards.

In this project, we tried to build our own water rocket that demonstrate real rocket. By experiment we look at the theories behind, for example the projectile motion. During the jet propulsion of the rocket, it is in linear project. Therefore, we will use Cartesian coordinate to represent the displacement and the velocity.