Question
State and explain the principle of conservation of linear momentum and establish it from Newton’s third law of motion.
Answer
The principle of conservation of linear momentum states that the total momentum of a system of objects remains constant if no external forces act on the system. This principle can be established from Newton’s third law of motion, which states that every action has an equal and opposite reaction. When two objects interact, they exert equal and opposite forces on each other, which means that the total momentum of the system remains constant. The forces acting on each object may be different in magnitude, but their effects on the momentum cancel out each other. This principle of conservation of linear momentum has wide applications in many areas of physics and has helped scientists to understand and explain many phenomena in the natural world.