Rakettiin

Rakettiin is a Finnish word that translates to "rocket" in English. It refers to a projectile or vehicle that derives its thrust from the expulsion of hot gas or other matter. Rockets are primarily used for propulsion in space travel, military applications, and scientific research.

The fundamental principle behind a rocket's operation is Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction. A rocket engine expels mass (propellant) at high velocity in one direction, generating an equal and opposite force that propels the rocket forward.

There are various types of rockets, broadly categorized by their propellant. Liquid-propellant rockets use a liquid fuel and a liquid oxidizer that are mixed and ignited in a combustion chamber. Solid-propellant rockets use a pre-mixed solid propellant that burns once ignited. Hybrid rockets combine elements of both.

Historically, rockets have played a significant role in exploration and defense. The development of rocketry led to the space race and continues to be essential for launching satellites, sending probes to other planets, and enabling human spaceflight. In military contexts, rockets are used as weapons for bombardment and as components of missiles. The study and engineering of rockets are part of the field of astronautics and aerospace engineering.