The rocket can send the spacecraft into orbit around the earth, and it can also send satellites and various detectors into space. When it comes to rockets, we will think of space flight.
We have all done this game: first blow into the balloon, then tighten the opening, then let go, the balloon will squirt and rush out in the opposite direction.
Let’s take another example of a simple rocket. If there is a small car on a smooth track, the machine is equipped with a machine gun at the end. Every time the machine gun shoots a bullet, the car moves forward a little. As the bullets are shot one by one, the speed of the car is getting faster and faster. It is conceivable that the machine gun fires a bullet every time, and the car receives a forward thrust. This force is the reaction force of the bullet on the car, which is also the driving force of the rocket.
In order to send spacecraft into space, the rocket’s engine must have strong power: engineers must design engines based on specific principles. The first person to describe this particular principle is the great scientist of the late 17th century in the United Kingdom, Isaac Newton. . Newton’s law is a law describing the universal gravitation and the motion of objects. The contents of his second and third laws describe the relationship between the force and motion of an object. From this we can know how the rocket advances in space.
Newton’s second law states that the force of an object in motion depends on its mass and its acceleration. Therefore, in order to obtain a horsepowered rocket, it must be ensured that it emits a lot of high-speed moving materials every second.
Newton’s third law is to say that as long as there is a force between two objects, the force and the reaction force must appear in pairs, and the size is equal and the direction is opposite. In the case of the rocket, the rocket’s force on the jet causes the jet to be ejected at a high speed, and the jet will simultaneously give the rocket an opposite force to propel the rocket forward.
The rocket carrying the spacecraft pushes back the gas generated by the fuel combustion to gain forward momentum. In fact, no matter what is pushed backwards, solid particles, liquids, or even atoms or protons, neutrons, and electrons can gain forward momentum.
Some people may think that the rocket is driven by the gas to push the gas in the surrounding environment to get the recoil, but in fact, the gas itself makes the rocket have such a powerful force. In fact, because there is no air in space, the rocket does not have to overcome air resistance when moving forward, so it is easier to move forward than in an airy environment. Moreover, the friction between the surface of the rocket and the surrounding environment is zero, which means that the rocket will not have any resistance to slow it down after starting. In addition, the spacecraft in space is not subject to gravity and has no weight, so even a small thrust can give the spacecraft a great speed.