stationary wave條件

The two travelling waves must be of EQUAL AMPLITUDE.

Stationary wave is characterized by the presence of nodes and antinodes. If the two waves forming the stationary wave are not of the same amplitude, nodes (positions where there are entirely no vibration, i.e. zero amplitude) would never be formed.

Also, the two waves need to be 180 degrees out of phase. This is the reason why stationary waves are usually formed from the superposition of a wave and its reflection.

不需要。


Stationary wave 是由兩個同性質的波(wave of same nature)沿兩個相反方向而互相干涉(interference)的效果。在一個closed system入面，只要wave的frequency乎合string的resonance frequency，stationary waves便可以出現。

兩個wave一定要有以下的性質。

a. 它們有一個固定的相位差(phase difference)，簡單說即要同頻率(same frequency)。

b. 它們要是同性質的。

c. 它們的amplitude要是相似的(similar)，不一定要相同。