Sir Isaac Newton (1687) described how forces affect the motion of objects. These three laws are the foundation of Classical Mechanics.

"An object at rest stays at rest, and an object in motion stays in motion — unless acted upon by an external force."

🧠 What it means:

Objects are lazy — they resist changes to their state of motion.

• A book on a table won't move until you push it.
• A rolling ball won't stop unless friction or a wall acts on it.

🔑 Key Concept — Inertia

Inertia = the tendency of an object to resist change in motion. More mass = More inertia (harder to move or stop)

🌍 Real-life example:

• You lurch forward when a car brakes suddenly — your body wants to keep moving!
• A tablecloth pulled quickly leaves dishes behind (dishes have inertia).

"Force = Mass × Acceleration"

🧠 What it means:

• More force → more acceleration
• More mass → less acceleration (for the same force)

🌍 Real-life example:

• Kicking a football 🏈 vs kicking a boulder — same force, very different accelerations.
• A cricket ball bowled fast needs more force than a slow delivery.

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

🧠 What it means:

Forces always come in pairs. If object A pushes on B, then B pushes back on A with the same force but in opposite direction.

You push wall ──→ ←── Wall pushes you back (Action) (Reaction)

⚠️ Common Beginner Confusion:

"If forces are equal, why does anything move?"

Because the forces act on different objects! The wall pushes you back, not itself.

🌍 Real-life examples:

Law 1 tells you when things move (only when forced). Law 2 tells you how much they move. Law 3 tells you forces never act alone.

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