Question

How does Newton's 3rd law apply to rockets?

Answer 1

Newton's third law of motion:

1. In $1686\text{'}s$ "Principia Mathematica Philosophiae Naturalis," Sir Isaac Newton introduced his three laws of motion for the first time. His third law argues that there is an equal and opposite reaction to every action (force) in nature.
2. In other words, if object $A$ exerts a force on object $B$, then object $B$ also exerts a force that is opposite and equal to the force that objects $A$ exerts on object $B$. You'll see that the forces are applied to various items.
3. The action-reaction principle is crucial in aircraft engineering. The creation of thrust by a rocket engine can be understood via Newton's third law. In a rocket engine, fuel and an oxidizer are burned to produce hot exhaust gas. The hot exhaust gas from the rocket accelerates to the back of the rocket after passing through the nozzle. On the engine mount, a pushing force is generated in response. Newton's second equation of motion describes how the thrust accelerates the rocket.

The third law of motion of Newton deals with these two forces, which are referred to as action and reaction forces. Newton's third law is officially expressed as follows: There is an equal and opposite reaction to every action. The implication of the statement is that there are always two forces acting on the two interacting objects.

Hence, the rocket is accelerated or propelled in the opposite direction.