Physics

Problem

A boy standing midway between two tall, parallel cliff faces claps his hands once every

0.50\,\text{s}

. If the speed of sound in air is

340\,\text{m}\,\text{s}^{-1}

, what is the greatest distance he can stand from each cliff so that the echo of any clap returns before he produces the next clap? a)

34\,\text{m}

85\,\text{m}

170\,\text{m}

42.5\,\text{m}