Question

A stone is dropped into a well 19.6m deep and the impact pf sound is heard after 2.056 seconds. Find the velocity of sound in air

Answer 1

$t=t_1+t_2$

$h=gt_1^2/2\to t_1=\sqrt{2h/g}=\sqrt{2\cdot 19.6/9.81}\approx1.999\ (s)$

$t_2=h/v$

$2.056=1.999+19.6/v\to v=19.6/0.057\approx344\ (m/s)$ . Answer