Swing (seat)

A swing ( niederd. Schukel, bavarian Hutschn, bern German Rytiplampi, zentralschweizerisch Rytiseili ) is a suspension seat with which you can rocking back and forth. Swings are common on playgrounds and in the garden; they are also available in the room. The momentum Get done by stretching and bending movements with the arms and legs or by pushing off from a fixed point. There are swings for children and for adults.

Swings that are in public areas, must, like all other playground equipment, the playground equipment standard EN 1176 correspond.

Cultic significance did the ancient Greek rocking hard ( Aiora ) at the time of the grape harvest.

Physics of swinging

If a swing deflected from its rest position, it oscillates back and forth a few times until the frictional forces bring their movement to a standstill. In order to maintain the rocking motion or even to intensify, so the rocking person physical work to be done. Such an active Swinging is a driven pendulum in the physical sense. Two different methods of supplying energy are used.

Energy supply by shifting the center of gravity

The more effective of the two methods is back is to shift the center of gravity of your own body during the passages of the deepest point upwards to the suspension now and in the moments of standstill at the reversal points again. This method is used especially on the swings while standing, where you go at the turning points in the squat and at the lowest point in each straightens again. As you raise it work against gravity and the centrifugal force must be made. The latter causes an energy supply, which leads to an increase in the speed at the lowest point, and thus drives the reciprocating motion.

The power supply is most effective when the focus increase is exactly at the lowest point, because at this moment the centrifugal force and thus the work to be performed are maximal. In practice, however, it is usually sufficient to spread the raising of the center of gravity of the entire phase of the pendulum motion of a point of reversal to the next. Commuting in the seats usually happens only during the forward phase of the pendulum motion, the person from the supine to upright position passes ( see Figure ), thus raising the center of gravity. During the backward phase, usually the upright posture is retained, so that no energy is supplied.

This conversion of kinetic energy into work performed by mass shift can be explained physically using the conservation of angular momentum. At the lowest point of the pendulum motion only forces acting in the direction of the axis of rotation. Therefore, the angular momentum remains almost constant, even if the mass is displaced from the pivot point out at this stage for a moment. However, this shift corresponds to a decrease of the moment of inertia of the system. Since the angular momentum is the product of moment of inertia and angular velocity, so the angular velocity must increase. The situation is comparable to that of the spins effect in which also by mass transfer of the pivot point towards an acceleration of the rotational movement is obtained.

From these considerations it also follows that it is most effective to perform the lowering the center of gravity at the moment of arrest, as it would in any other moment on the pirouette effect of the pendulum motion of extracting energy. Potential energy that is released upon lowering of the center of gravity at the moment of stoppage, does not lead to a change in the speed in the direction of the pendulum movement, and therefore not lead to a change in the maximum deflection of the swing. The same applies to the work being done on raising the lowest point against the pull of gravity. This is especially plausible if one considers that this is totally ineffective at raising a swing at a standstill.

Supply of energy through rotational movement of the body

The transition between sitting upright and the supine position corresponds not only to a shift in focus, but also a rotational movement of the body with the seesaw in about a rotational axis. In practice a large part of this rotational movement is performed at the turning point, in particular at the rear. The introduction of such a rotational motion corresponding to the generation of angular momentum. Since the pendulum rests at the turning point, it has the total angular momentum zero. Due to conservation of angular momentum, therefore, the angular momentum of the rotating body by means of a second must be compensated. This, however, only a rotational movement of the pendulum is in question as a whole. Since they must be opposite to the movement of the body, is one that at the turning point lifting a piece of the swing and thus enhances the pendulum motion.

This method is also applicable on the swings while standing. It is therefore possible to actively sway in the stretched state by shifting his upper body on the front position to the front and at the rear backwards, which corresponds to a rotational movement of the body. This drive through the exchange of angular momentum between the body motion and the swing as a whole, it is thanks to ever that you can initiate a rocking motion on a swing at rest without bumping through another person. With the method described above a pure shift in focus is not possible.

Hazards at a chain or rope swing

Again and again, reports of experiments to rock higher than with a normal rope swing to the horizontal deflection. At the peak of the deflection of the swing remains momentarily at rest, then, the force of gravity to commute back. Other than a bar, a rope swing, the above horizontal not force on a circular path, the swing just falls down.

Swings as rides and the circus

There are also numerous rides at fairs with swings. Here, the drive either by the passenger (small swinging ship ) or machine can take place. The mechanical drive is often done electrically using a stationary air-filled tire, runs to the bottom of the passenger gondola along as soon as it passes over it. By switching over the rotational movement of an increase in the swing amplitude is achieved.

In the circus swings freely hanging from ropes or chains, such as the swing or floating triangle, the trapezoid is called. Comparable to the springboard, also a special swing construction is used in the artistry. Here are two people on a board which is suspended as a swing, at one end of the board is a flat, wedge-shaped platform is installed to allow for a safe jump. The pivot point is located as in the swing boat, several meters above the board. After the construction of sufficient momentum, one of the people jumping from the highest point and can by taking advantage of another pulse, perform on their way through the air somersaults appropriate.

More pendulum swing

Hugo Kükelhaus has developed for his field of experience of the senses several swings to make pendulum oscillations physical- emotional- social experience.

• Temporal differences in pendulum movements, he shows by rocking with different lengths (three- time shuttle ). A plurality of balls suspended in the same cross-beam and commute with each other, and thus different lengths of cables. Despite the different length pendulum rhythm, there are from time to time moments, where all three spheres lie on exactly one line.

• The double swing is a double swing for two people sitting opposite, are connected by cables to the opposite swing at each swing both chains in the upper quarter. They thus form a coupled system. The rocking motion of a is transferred to the swing movement of the other. This interdependence experienced directly. The kinetic energy is transmitted through the connected cables from the moving person on the swing of the person at rest, which is thereby set in motion and turn the rocking slows person thereby.

Pendant stone

The pendant stone is an additional tool for sensory perception for children and adults according to the concept of Kükelhaus. The free-swinging rock block is suspended at about 5 to 8 meters high pyramid erected bar on a steel cable and provides a seat for one person (or two children). He makes the quiet - inertial mass and its kinetic energy and experience " offset inescapable the sensation block all Mithandelnden in vibration. Life is vibration. " ( Kükelhaus ). They are used in special education, experience on fields or in part, on motion places for seniors.

The rocking motion is to be moderate and circular. The Swinging person concentrates with closed eyes on her inner body awareness. It may succeed, consciously and completely hide the perception of the environment and just to hear your own breath. Medical evidence is the calming effect and the concentration promotion especially among young people and among people with disabilities. The pyramid-shaped suspension of the circular pendulum also stimulates esoteric symbols of force fields.

Other swings

A power swing or a rocking bed or a bird's nest swing or a rocking network is a network in which several people can sit. On this net directions can be rocked due to a 4- point suspension in all horizontal.

No swings in the real sense are also rocking stones mentioned Wackelsteine ​​. It involves large blocks of rock, the balance despite their mass move easily on its base.