noun
数据来源：WordNet
To vibrate three times as fast , or once in every third part of a second , the cord had to be only one-ninth of39.1 inches in length .
要使其摆动速度提高三倍，亦即每三分之一秒摆动一次，绳子的长度则只能是39.1英寸绳子长度的九分之一。
one-ninthone-ninthone-ninth