Answer:h=40.69 m
Explanation:
Given
after 3 s you heard the sound of coin
speed of sound=343 m/s
let h be the height of well
[tex]h=ut+\frac{gt_1^2}{2}[/tex]
[tex]t_1=\sqrt{\frac{2h}{g}}[/tex]
While coming back time taken
[tex]t_2=\frac{h}{343}[/tex]
[tex]t_1+t_2=3[/tex]
[tex]\sqrt{\frac{2h}{g}}+\frac{h}{343}=3[/tex]
[tex]h^2-26059.25h+9\times 343^2=0[/tex]
h=26018.554, 40.69 m