Newton's Cradle Art in Motion, 1 Inch Balance Balls - Black Wooden BaseNewton's Cradle is a fun demonstration of physics in the principles of kinetic energy and conservation of momentum Elegant conversation piece for home or at the office High quality construction Neatly packed and secured in place to ensure that the strings are not tangled upon arrival Base measures 7. 25" x 4. 6" and each balance ball has a 1 inch diameter This Newton's Cradle is a fun demonstration of physics in action and demonstrates the principles