Physics

Problem

On a day when the air temperature is

20^{\circ}\text{C}

, the speed of sound is

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

. How far from a vertical cliff must a boy stand so that he can hear a distinct echo of his shout? a)

34\,\text{m}

3.4\,\text{m}

17\,\text{m}

171\,\text{m}