How does the rocket engine propell the rocket?

Answer 1

By Newton's 3rd law; for every action there is an equal and opposite reaction. It is like the recoil of a gun. The bullet goes out the barrel really fast and the gun kicks back in reaction. A less dangerous experiment is to sit still on a skateboard on level pavement while holding a heavy rock or other object. Throw the rock as hard as you can forward and you and the skateboard will start rolling slowly backward. The rocket engine is throwing out little rocks or bullets, in the form of trillions of gas molecules, and the reaction pushes the rocket in the other direction.

Answer 2

One of the basic principles of physics (Newton's Third Law) is that for every action (force) there is an opposite and equal reaction (force). The principle of a rocket motor may be understood by considering the example of a closed container filled with a compressed gas. Within this container the gas exerts equal pressure on every point of its walls. If a hole is punched in the bottom of the container, however, the gas at the bottom escapes and the pressure against the top of the container is no longer equalized. The internal gas pressure then pushes the container upwards in reaction to the jet of air escaping downwards. The amount of thrust developed by a rocket motor depends mainly on two factors, the velocity with which the burning gases leave the combustion chamber, and the mass of the burning gases.

Answer 3

By throwing a bunch of stuff out of the nozzle. According to Newton's third law, for every action, there is an equal and opposite reaction. So the rocket goes the opposite direction of the ejected stuff from the nozzle.

Answer 4

every action has equal opposite action. example when a cork is shot out of a bottle. the cork is pushing back on the bottle with the same force that pushed it out. that is why a Cannon is shot backwards when it is fired. the exhaust of a rocket's exerts energy away from the rocket which forces it forward. that why the trust or force must be greater then the weight of the rocket.

Answer 5

Both the above are right... to expand on their answers, the equation for thrust of a rocket is:

T = m_dot * v_e + (p2 - p1)*A_e

T = thrust
m_dot = mass flow rate (speed of fuel flow into the nozzle)
v_e = exhaust velocity (speed of exhaust gases)
p2 = nozzle exit pressure
p1 = ambient pressure (zero in vaccuum)
A_e = nozzle exit area

The first term is known as momentum thrust term
The second is known as pressure thrust which is usually less than 1-5 % of the total momentum thrust and is usually neglected.

As an example, the space shuttle solid rocket boosters burn about 1.1 million lbs of fuel in about 2 mins... or almost 10,000 lbs a second... they produce about 2.65 million lbf of thrust a piece, by ejecting the 10,000 lbs at about 8600 ft/s every second!

Answer 6

Using Newtons 3 rd law . And by throwing mass out.

When the rocket fuel burs it generates heat and the the pressure .This pressure throw the burnt fuel ( gas) out. The reactive force pushes the rocket up.