Paper+vs.+Balloon+Rockets

Paper Rockets

The flight of a paper rocket can be explained by forces and the laws of motion acting on it. Before the paper rocket is launched the forces on it are balanced. Friction and the inertia of the rocket keep it from moving. This shows that a object at rest stays at rest which is part of the first law of motion.

When the valve on the launcher is opened forces become unbalanced. The force of the air pushing on the rocket overcomes the force of friction and the inertia of the paper rocket. The paper rocket accelerates until it leaves the launcher. During the launch the air leaving the launcher pushes on the paper rocket and the rocket pushes back with an equal force on the air. The forces are in opposite directions, so this shows the third law of motion. The launcher and its support has more mass than the paper rocket, so the paper rocket takes flight.

In flight, the paper rocket is a projectile. The air from the launcher is no longer accelerating the paper rocket, The paper rocket keeps traveling horizontally due to its inertia. This show that an object in motion stays in motion which is another part of the first law of motion. Again forces are unbalanced because the paper rocket is slowing down due to air resistance and it is falling due to the force of gravity. In flight the paper rockets acceleration or change in motion is much less that when it was launched.

The paper rockets experiences the biggest unbalanced force and thus acceleration when it hits the wall and stops. The paper rocket pushes on the wall and the wall pushes back with an equal and opposite force. This again shows the third law of motion. The wall doesn't give-way, so the rocket is stopped very quickly in a very short distance causing a quick acceleration.