# Rocket

## Explanation

Rockets are non-air breathing aircraft and spacecraft that propel with the help of thrust generated by a rocket engine. As the propellant burns inside the combustion chamber, the hot expanding gases accelerate out of the nozzle, creating a forward thrust due to Newton’s third law of motion.

## Frequently Asked Questions

### How does a rocket work in the vacuum of the space?

Newton’s third law applies in space as well. When the propellants burn in the combustion chamber, the hot gas accelerates out of the nozzle. This mass of accelerating gases exerts an equal and opposite force on the chamber wall and pushes the rocket along the same axis as the gas leaves the nozzle. This is an example of the conservation of momentum. As the rocket expels a significant amount of mass through the nozzle, the momentum of the rocket changes to conserve the total momentum of the system.

This is expressed in Tsiolkovsky rocket equation as, $\Delta v = v_\text{e} \ln \frac {m_0} {m_f}$.