3️⃣ Newton's Third Law

Action & Reaction

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🍎 Newton's Third Law

The third law is all about pairs of forces. It tells us that forces always come in twos — whenever one object pushes on another, the second object pushes back just as hard!

📜

The Third Law

📜 Newton's Third Law:

For every action, there is an equal and opposite reaction.

This means that when you push on something, it pushes back on you with the same strength, but in the opposite direction. These two forces are called an action–reaction pair.

💡

Action and Reaction in Action

💡 Jumping Off a Boat:

When you jump forward off a small boat, the boat shoots backward! You pushed the boat back (action), and the boat pushed you forward (reaction). Both forces are equal, but they point in opposite directions.

📝 Everyday Examples:

  • Swimming: you push the water backward, the water pushes you forward 🏊
  • Walking: your feet push back on the ground, the ground pushes you forward 🚶
  • A rocket: pushes hot gas down, the gas pushes the rocket up 🚀
  • A balloon: lets air rush out one way and zooms off the other way 🎈
⚖️

Equal but Opposite

The two forces in an action–reaction pair are always:

  • Equal in size (same strength)
  • Opposite in direction (pointing the other way)
  • Acting on two different objects (one on each)
⚡ Fun Fact: Rockets can fly in outer space — where there's no air to push against — because of Newton's Third Law. They push their exhaust gases out, and those gases push the rocket forward!

📚 Quick Summary

3️⃣ Third Law

Every action has an equal and opposite reaction

👫 In Pairs

Forces always come in action–reaction pairs

⚖️ Equal & Opposite

Same strength, opposite directions

🚀 Rockets

Push gas out to thrust themselves forward

➡️ Keep Exploring

1️⃣ Newton's First Law

Review the law of inertia.

2️⃣ Newton's Second Law

Review force, mass, and acceleration.