{"product_id":"happy-sad-ball-elastic-and-inelastic-balls-25mm-set-of-2","title":"Happy \u0026 Sad Ball Elastic and Inelastic Balls 25mm. Set of 2.","description":"Happy and Sad Balls are used to show the relationship between elastic and inelastic collisions. While both balls share an identical makeup between mass, density, and appearance, one will bounce, while the other will not. They are sold as a pair.\u003cbr\u003e\u003cbr\u003eThe Happy Ball consists of standard neoprene that has low hysteresis, low surface friction, and weak intermolecular forces. The Sad Ball consists of Norsorex that has high hysteresis, high surface friction, and stronger intermolecular forces.","brand":"GSC International","offers":[{"title":"Default Title","offer_id":49507540730133,"sku":"GSCHSBL-01","price":7.8,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0857\/4897\/3845\/files\/hsbl-01.jpg?v=1761840966","url":"https:\/\/unitedsupplycorp.com\/products\/happy-sad-ball-elastic-and-inelastic-balls-25mm-set-of-2","provider":"United Supply Corp.","version":"1.0","type":"link"}