What is Newton's Cradle?

Newton's Cradle is a device that demonstrates conservation of momentum and energy using a series of swinging spheres. When one sphere is lifted and released, it strikes the stationary spheres, transmitting a force through them that pushes the last sphere outward. The device is named after Sir Isaac Newton and is a classic desktop physics toy.

How does Newton's Cradle demonstrate conservation of momentum?

When a ball on one end is pulled back and released, it strikes the next ball, transferring its momentum through the chain. Because momentum (mass × velocity) must be conserved in the collision, and the balls have equal mass, the last ball swings out with approximately the same velocity. Lifting two balls results in two balls swinging out on the other side.

Why does a Newton's Cradle eventually stop?

In reality, Newton's Cradle gradually loses energy due to friction at the pivot points, air resistance, sound energy produced on impact, and imperfect elasticity of the collisions. These non-conservative forces convert kinetic energy into heat and sound, causing the amplitude to decrease over time until the cradle stops.

What is an elastic collision?

An elastic collision is one in which both momentum and kinetic energy are conserved. In a perfectly elastic collision between equal masses where one is initially at rest, the moving object stops completely and the stationary object moves with the original velocity. Real-world collisions are never perfectly elastic, but Newton's Cradle approximates elastic behaviour closely.

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🧪 Newton's Cradle Simulator

Interactive Newton's Cradle simulation demonstrating conservation of linear momentum and kinetic energy through elastic collisions. Adjust mass, elasticity, and damping to explore classical mechanics principles.

Physics & Mechanics2DModerate60 FPS

⚙ Under the hood

This simulation demonstrates Newton’s Laws of Motion and conservation of momentum and energy through a classic demonstration with a Newton’s cradle. Users can observe the transfer of energy and the resulting collisions.

Newton's CradleMomentum Energy

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install