If we place our finger exactly half way along the string and pluck again,the string vibrates,we observe a standing wave but the midpoint does not move. or node The amplitude at the midpoint is zero-a Node When one half of the string is up,the other is down,the two halves vibrate out of phase with one another. This is the first Harmonic of the wave. Ch02 Structure and Properties (landscape) Page 3Ch02 Structure and Properties (landscape) Page 3 If we place our finger exactly half way along the string and pluck again, the string vibrates, we observe a standing wave but the midpoint does not move. The amplitude at the midpoint is zero – a Node. When one half of the string is up, the other is down, the two halves vibrate out of phase with one another. This is the first Harmonic of the wave