# A pendulum is a wave

## Try vibrations and waves

### A01 pendulum

##### A01.01 Thread pendulum, mathematical pendulum

A thread pendulum comes so close to the values ​​of a mathematical pendulum that one can study the theoretical predictions on it. There are three pendulums. Two have the same thread length and different pendulum masses, with which the same period of oscillation (T = 2s) can be shown. The thread length of the third pendulum is chosen so that half the period of oscillation (T = 1s) results.

Presentation: projection with an arc lamp

Evaluation: works

##### A01.02 spring pendulum

Spring pendulums with different springs and pendulum masses are built up. The oscillation periods can be compared with a stopwatch.

Presentation: direct or projection with an arc lamp

Evaluation: works

##### A01.04 Physical pendulum; Reversion pendulum

An extended body can be suspended from various pivot points. This results in different periods of oscillation, which are measured with a stopwatch.

### A02 vibrations

##### A02.01 Synchronization of oscillation / rotary motion

A spring pendulum is projected next to a rotating disk with a pen using an arc lamp. If the oscillator amplitude and rotation frequency are set correctly, both movements are synchronous.

##### A02.02 vibrating liquid in the U-tube

There is colored water in a U-tube that can be made to vibrate.

### A03 composite vibrations

##### A03.01 coupled gravity pendulum (small)

Two gravity pendulums are connected by a spring. This can be used to demonstrate movement in the same direction and in opposite directions as well as the exchange of energy between the pendulums.

##### A03.04 Summer field pendulum

The Sommerfeld pendulum is a spring pendulum in which the oscillating mass has a pronounced moment of inertia. Therefore, the system can perform two oscillations. On the one hand the elastic longitudinal oscillation and on the other hand a torsional oscillation. After deflection, the types of oscillation alternate.

Presentation: direct or projection with an arc lamp

Rating: good

### A07 standing waves

##### A07.01 Standing wave model

The model shows 2 sine waves and the standing wave resulting from the superposition of these waves.