Newton’s third law best Demonstration ever by Prof Walter Lewin
Newton’s third law: If an object A exerts a force on object B, then object B must exert a force of equal magnitude and opposite direction back on object A.
This law represents a certain symmetry in nature: forces always occur in pairs, and one body cannot exert a force on another without experiencing a force itself.
This is an excerpt from Prof walter Lewin’s fairwell lecture on the 16th may 2011. He beautifully demonstrated Newton’s third law of motion at the end of this lecture.