Editing Newton's cradle (section)

==Operation==
[[File:Newton’s cradle slo mo.webm|thumb|Newton's cradle in [[slow motion]]]]
When one of the balls at the end ("the first") is pulled sideways, the attached string constrains it along an upward arc. When released it strikes the second ball and comes nearly, but not entirely, to a dead stop. The succeeding ball acquires most of the [[velocity]] of the first ball propagates the diminished momentum. Eventually the last ball, having received a successively diminished portion of the first's energy and momentum, begins the process anew in the opposite direction. Each impact produces a [[Theory of sonics|sonic wave]] that propagates through the medium of the intermediate balls. (Any efficiently elastic material such as steel suffices, as long as the [[kinetic energy]] is temporarily stored as [[potential energy]] in the compression of the material rather than being lost as [[heat]]. This is similar to bouncing one coin of a line of touching coins by striking it with another coin, and which happens even if the first struck coin is constrained by pressing on its center such that it cannot move.){{cn|date=July 2023}} In each phase of the process, efficient mechanical energy is lost; Newton's cradle is not a [[perpetual motion machine]]. This would stand true even in the absence of air resistance, as in a [[vacuum]]. 

There are slight movements in all the balls after the initial strike, but the last ball receives most of the initial energy from the impact of the first ball. When two (or three) balls are dropped, the two (or three) balls on the opposite side swing out. Some say that this behavior demonstrates the conservation of momentum and kinetic energy in elastic collisions. However, if the colliding balls behave as described above with the same [[mass]] possessing the same velocity before and after the collisions, then any function of mass and velocity is conserved in such an event.<ref>{{cite journal|last=Gauld|first=Colin F.|title=Newton's Cradle in Physics Education|journal=Science & Education|date=August 2006|volume=15|issue=6|pages=597–617|doi=10.1007/s11191-005-4785-3|bibcode=2006Sc&Ed..15..597G|s2cid=121894726}}</ref> Thus, this first-level explanation is a true, but incomplete, description of the motion.