Swing (seat)
For older children, swings are sometimes made of a flexible canvas seat, of a rubberized ventilated tire tread, of plastic, or of wood.
A common backyard sight is a wooden plank suspended on both sides by ropes from a tree branch.
Face-to-face tandem swings are known in some regions of North America as a "teeter-totter" (not to be confused with the seesaw which it superficially resembles).
Back-to-back tandems are typically in the baby bucket design, but with two pairs of leg holes, one on each side of the bench.
Tandem swings are typically suspended from their frame (as in kiiking) by steel bars, although ropes and chains may be used for those used only by smaller children.
There is a common myth that swinging first spread throughout China during the Spring and Autumn period (771–476 BC).
A terracotta sculpture of a woman sitting on a swing found at Hagia Triada dates to the Late New Palace period (1450–1300 BC).
[7][8] In Eastern Europe, Slavic traditions associate swinging with courting and with crop-fertility rituals.
Players attempt to rotate 360 degrees around a spindle, on a long swing consisting of a seat hung with steel bars.
Tubular metal sets were replaced with smaller swings made of woods and resins better suited for children.
When left to swing freely, the amplitude of motion will gradually decay due to air resistance and friction in the pivot.
The first is driven harmonic oscillation in which the driving force arises from the rotation of the rider's body as it transitions from one position to the other.
Case reported that this mechanism can be demonstrated by means of a bicycle wheel mounted on the end of a pendulum.
[17] Both mathematical modeling and experimental studies of human subjects have found that driven oscillation is the dominant mechanism for most seated and standing pumping motions.
[18][19] The second mechanism is parametric oscillation, where the driving force arises from varying a system parameter (in this case pendulum length) at a specific frequency.
If the center of mass of the swing-rider system shifts closer to the pivot point during the upward portion of the swinging motion, the moment of inertia is reduced and the swing gains kinetic energy due to conservation of angular momentum (the same mechanism that causes a figure skater to spin faster when they tuck their arms and legs closer to their body).
[20] Based on observations of U.S. children, Case noted, "Although it is certainly possible to pump a swing with the purely vertical motion one finds that this is not the mechanism of choice at the playground.
Typical seated pumping also includes a parametric contribution due to the rider sitting up as they approach the top of the forward swing, though the effect is small compared with the driven oscillation mechanism.
The same authors also derived an expression for the "critical" initial velocity which would allow the swing to make a full circular rotation:
[22] The most common injury is due to a fall, either by unintentionally letting go of the ropes or chains or by deliberately jumping out of the swing.
Swinging also helps teach the child rhythm and balance, and encourages social interaction as children must cooperate and play together.
