Pendulum

A pendulum ( formerly pendulum, from Latin pendere "hang" ) is a body rotatably mounted on an axis or a point outside its center of mass can oscillate about its own resting position. The pendulum frequency ( resonant frequency) of the pendulum depends on its length, but not of the pendulum mass from.

Pendulum types

Gravity pendulum

The to be moved by gravity into oscillation pendulum is the most widespread. It consists for example of a band or a bar, weighted at the free end of a mass. Bring to such a pendulum from its vertical resting position, it vibrates under the influence of gravity back and as long as no absorption occurs symmetrically about the deepest position of the center of mass - the rest position - on swing. The regularity of the oscillation period of a pendulum is used in mechanical clocks. Your pendulum must, they should go exactly to cover possible small and constant amplitude.

At the theoretical level, a distinction is gravity commuting the following two ways: The mathematical pendulum is an idealized model for the general description of the pendulum oscillations. The physical pendulum differs from the mathematical pendulum by him in the shape and size of the pendulum bob is taken into account, which is why the behavior of physical pendulum rather corresponds to that of real pendulums.

With the Foucault pendulum, the Earth's rotation could be detected: the Coriolis force acts from the outside on the swing by changing its vibration level and it distracts the vibration to vibration in a recurring pattern.

Spring pendulum

Spring pendulum feature in contrast to the gravity pendulum on its own, largely proportional restoring forces for their repeated deflection. Their resonant frequency is independent of the gravity.

There are the following options:

When linearly moving spring pendulum or spring oscillator, the restoring force is caused by torsion in a helical spring.

The torsion pendulum ( torsion pendulum ) swinging in the form of a rotary motion with a vertical axis located at a twisting wire or strip; the restoring force is generated by torsion.

For three oscillators with spiral spring (eg balance ) the restoring force is applied by bending in the spiral spring

Coupled pendulums

Be coupled pendulum for physical experiments. For example, one connects pendulum together with a spring. One can very well observe the phenomenon of beat on their movements. Bonded atoms (eg in a molecule or in a solid state ) can approximately be described by such a model of coupled pendulums.

Double pendulum serve as a demonstration of chaotic processes, as the movements are to be designated as such in double pendulums. Linear ( for example by means of springs ) coupled pendulums generate complex vibration patterns by the fundamental oscillation of the so-called self-oscillation forms or modes of vibration are superimposed with the corresponding natural frequencies.