Distinction Between Travelling and Standing Waves

Travelling Waves

1. Particular conditions of the medium namely crests and troughs or compressions and rarefactions appear to travel with a definite speed depending on density and elasticity (or tension) of the medium.

2. The amplitude of vibration of all the particles is the same.

3. All the particles pass through their mean positions with maximum velocity one after the other.

4. Energy is transferred from particle to particle with a definite speed.

5. In a travelling wave the particles attain their maximum velocity one after the other.

6. In a travelling wave each region is subjected to equal strains one after the other.

7. There is no point where there is no change of density.

Standing Waves

1. Segments of the medium between two points called nodes appear to contract and dialate. Each element of the medium vibrates to and fro like a pendulum.

2. At nodes the amplitude is zero but at antinodes the amplitude is maximum.

3. At nodes the particle velocity is zero and at antinodes it is maximum.

4. The energy surges back and forth in a segment but does not move past a point.

5. In a stationary wave the maximum velocity is different at different points. It is zero at nodes but maximum at antinodes. But all the particles attain their respective maximum velocity simultaneously.

6. In case of standing waves strain is maximum at nodes and zero at antinodes.

7. Antinodes are points of no change of density but at nodes there is maximum change of density.