Chapter 7, Problem 10A

Identify the force that propels a rocket.

To determine

The force that propels rocket.

Explanation of Solution

Introduction:

Action and reaction forces appear in pair. For every action there is equal and opposite reaction.

Rocket propel in vacuum or in atmosphere by firing a cannon ball. To move forward or lift up, rocket needs a reaction force. Rocket fires a cannon ball while moving. During firing exhaust gases are expelled out. These exhaust gases exerts force on the rocket. Also in vacuum cannon ball exerts reaction force on the rocket in opposite direction which lifts the rocket up.