Standing Waves on a String

Pluck a string fixed at both ends into a chosen harmonic — adjust its length, tension, and mass per unit length to see how fast, and in how many nodes and antinodes, it vibrates.

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What you can adjust

String length
0.3 – 3 m
Tension
0.5 – 50 N

Higher tension makes waves travel faster along the string, raising every mode's frequency.

Linear density (mass/length)
0.001 – 0.05 kg/m

A heavier string (per unit length) carries waves more slowly, lowering every mode's frequency.

Harmonic (mode number)
1 – 6

n=1 is the fundamental (1 antinode, both ends fixed). Higher n packs more nodes and antinodes onto the same string and raises the frequency.

Amplitude
0.01 – 0.3 m

How far the string swings from its rest position at an antinode — doesn't change frequency, just how big the wave looks.

About this simulation

What it shows

A string fixed at both ends vibrates in a chosen pattern, with points that stay still (nodes) and points that swing the most (antinodes).

The key idea

Waves travel along the string at v = √(T/μ) and fit the string only in whole numbers of half-wavelengths. The frequency of harmonic n is n × v / 2L, so higher harmonics have more nodes and higher pitch.

Try this

Change Harmonic (mode number) from 1 to 3: the string shows three antinodes and vibrates at three times the frequency.