Newton’s Cradle is that elegant desktop toy with a row of swinging metal balls — and it’s also a brilliant demonstration of classical mechanics, especially conservation of momentum and conservation of energy.

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⚙️ How It Works

A standard Newton’s Cradle consists of:
• 5 (or more) identical metal balls suspended in a row by thin wires so they just touch each other.
• When you lift and release one ball at one end, it hits the row and one ball on the opposite end swings out, while the middle balls stay almost still.

Let’s break down what’s happening:
1. 🔄 You lift one ball → it gains potential energy.
2. 🧲 You let it fall → it converts that to kinetic energy.
3. 💥 It hits the next ball → energy and momentum transfer through the line.
4. 🎯 The last ball pops out → same speed, same height (ideally), conserving both energy and momentum.

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📐 What Laws Are Demonstrated?

✅ 1. Conservation of Momentum

The total momentum before and after collision stays the same.

✅ 2. Conservation of Energy

The total kinetic energy remains constant (in an ideal case with no friction or sound loss).

✅ 3. Elastic Collisions

Newton’s Cradle approximates elastic collisions, where no energy is lost to deformation or heat.

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🔄 What If You Lift More Than One Ball?
• Lift 2 balls → 2 balls swing out on the other side.
• Lift 3 → 3 come out.
That symmetry shows how well momentum and energy pass through the system.