In a travelling wave, the amplitude is . However, in a standing wave, the amplitude is .

In a traveling wave, the amplitude is the maximum displacement of a point on the wave from its rest position. It is constant throughout the wave and does not change with time or position.

Step 1: Understand the wave. A traveling wave is a wave in which the points of maximum and minimum displacement, known as antinodes and nodes, move in the direction of the wave.

Step 2: Identify the amplitude. The amplitude is the distance from the rest position to an antinode, and it is the same for all points on the wave at a given time.

However, in a standing wave, the amplitude varies from zero at the nodes to a maximum at the antinodes.

Step 1: Understand the wave. A standing wave is a wave in which the points of maximum and minimum displacement, known as antinodes and nodes, do not move. This is the result of the interference of two waves moving in opposite directions.

Step 2: Identify the amplitude. The amplitude varies along the wave, being zero at the nodes and reaching a maximum at the antinodes. The amplitude at a given point on the wave does not change with time.