A rocket in its simplest form is a chamber enclosing a gas under pressure. A small opening at one end of the chamber allows the gas to escape, and in doing so provides a thrust that propels the rocket in the opposite direction. A good example of this is a balloon. Air inside a balloon is compressed by the balloon's rubber walls. The air pushes back so that the inward and outward pressing forces are balanced. When the nozzle is released, air escapes through it and the balloon is propelled in the opposite direction.
When we think of rockets, we rarely think of balloons. Instead, our attention is drawn to the giant vehicles that carry satellites into orbit and spacecraft to the Moon and planets. Nevertheless, there is a strong similarity between the two. The only significant difference is the way the pressurized gas is produced. With space rockets, the gas is produced by burning propellants that can be solid or liquid in form or a combination of the two.
One of the interesting facts about the historical development of rockets is that while rockets and rocket-powered devices have been in use for more than two thousand years, it has been only in the last three hundred years that rocket experimenters have had a scientific basis for understanding how they work.
The science of rocketry began with the publishing of a book in 1687 by the great English scientist Sir Isaac newton. His book, entitled Philosophiae Naturalis Principia Mathematica, described physical principles in nature. Today, Newton's work is usually just called the Principia. In the Principia, Newton stated three important scientific principles that govern the motion of all objects, whether on Earth or in space. Knowing these principles, now called Newton's Laws of Motion, rocketeers have been able to construct the modern giant rockets of the 20th century such as the Saturn V and the Space Shuttle. Here now, in simple form, are Newton's Laws of Motion.
Newton's Second Law
This law of motion is essentially a statement of a mathematical equation. The three parts of the equation are mass (m), acceleration (a), and force (f). Using letters to symbolize each part, the equation can be written as follows:
f = maBy using simple algebra, we can also write the equation two other ways: a = f/mm = f/aLet's apply this principle to a rocket. Replace the mass of the cannon ball with the mass of the gases being ejected out of the rocket engine. Replace the mass of the cannon with the mass of the rocket moving in the other direction. Force is the pressure created by the controlled explosion taking place inside the rocket's engines. That pressure accelerates the gas one way and the rocket the other.
Some interesting things happen with rockets that don't happen with the cannon and ball in this example. With the cannon and cannon ball, the thrust lasts for just a moment. The thrust for the rocket continues as long as its engines are firing. Furthermore, the mass of the rocket changes during flight. Its mass is the sum of all its parts. Rocket parts includes engines, propellant tanks, payload, control system, and propellants. By far, the largest part of the rocket's mass is its propellants. But that amount constantly changes as the engines fire. That means that the rocket's mass gets smaller during flight. In order for the left side of our equation to remain in balance with the right side, acceleration of the rocket has to increase as its mass decreases. That is why a rocket starts off moving slowly and goes faster and faster as it climbs into space.
Newton's second law of motion is especiaily useful when designing efficient rockets. To enable a rocket to climb into low Earth orbit, it is necessary to achieve a speed, in excess of 28,000 km per hour. A speed of over 40,250 km per hour, called escape velocity, enables a rocket to leave Earth and travel out into deep space. Attaining space flight speeds requires the rocket engine to achieve the greatest action force possible in the shortest time. In other words, the engine must burn a large mass of fuel and push the resulting gas out of the engine as rapidly as possible. Ways of doing this will be described in the nextchapter, practical rocketry..
Newton's second law of motion can be restated in the following way: the greater the mass of rocket fuel burned, and the faster the gas produced can escape the engine, the greater the thrust of the rocket.
Putting Newton's Laws of Motion TogetherAn unbalanced force must be exerted for a rocket to lift off from a launch pad or for a craft in space to change speed or direction (first law). The amount of thrust (force) produced by a rocket engine will be determined by the mass of rocket fuel that is burned and how fast the gas escapes the rocket (second law). The reaction, or motion, of the rocket is equal to and in the opposite direction of the action, or thrust, from the engine (third law).For every action there is an equal and opposite reaction, the force of the rocket's output translates to the forward motion of the rocket.
the rocket works on newtons law, which states that every action has an equal reaction in opposite direction. the rocket releases a jet of hot gases which propels it to the space:)
newtons 3rd law
It all depends on the fuels available energy, the mass of the craft, and any force the craft may have to overcome (see Newtons second law of motion). Also, although it'd take a while one could conceivably cross the entire universe on one gallon. As long as nothing counteracts the force of the propellant the craft will never stop (see Newtons first law of motion).
The stages of a rocket going into space: The first stage of a rocket is used to acquire the acceleration of a rocket. When the fuel of the first stage is exhausted ,it detaches from the rockets and drops off. The velocity at this stage becomes the initial velocity of the second stage .Now the second stage is ignited ,the rocket gains acceleration and it's velocity foes on increasing . The removal of the surplus mass contained in the first stage helps in attaining the higher velocity .When the fuel of the second stage is exhausted ,it too detached from the rocket .Finally at the third stage , the rocket starts off with the required velocity.
The products of the burning fuel are ejected from the rocket at high velocity. In accordance with Newton 's Third Law, this action generates an equal and opposite reaction on the rocket. The forward forward force acting on the rocket accelerates it.
newtons law of motion
F = m Am = 0.19A = 11F = (0.19) x (11) = 2.09 newtons upwardBut there is another force on the rocket = (m g) = (0.19) x (9.8) = 1.862 newtons downward.The engine also has to cancel this force.Total engine thrust required = (2.09 + 1.862) = 3.952 newtons.
5 Million Newtons was the pressure exerted by Saturn v rocket
With newtons laws of motion we can expand and improve technology because the three laws are the base of rocket science
For every action there is an equal and opposite reaction, the force of the rocket's output translates to the forward motion of the rocket.
newtons third law
the rocket works on newtons law, which states that every action has an equal reaction in opposite direction. the rocket releases a jet of hot gases which propels it to the space:)
This depends on the weight of the rocket, weight being the mass of the rocket multiplied by earth's gravitational pull. To take off, the rocket needs to exert force larger than the weight, and for a sufficient amount of time to break out of orbit. For instance, if the rocket had a mass of 1kg, it'd exert (1 * 9.8), or 9.8 Newtons of force towards to ground via it's weight (9.8 being the acceleration towards the ground due to gravity). This means that to start to accelerate away from the ground, the rocket would need to exert force higher than 9.8 Newtons. If your hypothetical rocket has a mass of x kg, then it will need to exert a force greater than 9.8x newtons, ignoring air resistance and decaying of the gravitational field.
newtons 3rd law
Newton's Third Law: "For every action there is an equal and opposite reaction."
the principle behind working of a rocket is newtons 3rd law of motion which states that every action has equal and opposite reaction