Question

Blow a balloon and let it go. You will find it moving in the direction opposite to the direction in which the air is ejected. This demonstrates :

• A. the principle of rocket propulsion
• B. the principle of combustion
• C. the principle of conservation of energy
• D. None of the above

Answer 1

Answer: (A)

the principle of rocket propulsion

The principle of rocket propulsion works on the 'Newton's Third Law of Motion'. It states that, 'to every action, there is always an equal and opposite reaction'.

In the case of a rocket, the engine emits hot burning gases in the downward direction. These gases apply an equal and opposite reaction force to the rocket in the upward direction.

This is how a rocket is propelled.

Rocket propulsion is similar to the example of the situation in which, if we blow a balloon and let it go, it starts moving in the direction opposite to the direction in which the air is ejected.

Balloon forces out the air inside it. The air applies an equal and opposite reaction force to the balloon.