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Fun Science Physics Toys Black Large Newton's Cradle Pendulum Balance Balls 5 Beads Perpetual Motion Desk Toy Wooden Base Balance Balls for Office and Desk Decorations

Five steel balls on strings that prove conservation of momentum in the most satisfying possible way — a physics toy and desk sculpture in one. Perfect for science teachers, office desks, or anyone who finds kinetic motion genuinely hypnotic. Click one end and let it run — it hasn't gotten old in fifty years of desks.

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