A stone is dropped into a well and sound of impact of stone with water is heard after 2.056 second of the release of stone from top If g 980 cm/`s^(2)` and velocity of sound is 350 m/s. Then depth of well is :

Options

A. 19.6 m
B. 9.8 m
C. 30 m
D. 7 m

Answer

A

Explanation

t = `t_(1) + t_(2)` .
`t = sqrt((2h)/(g)) + (h)/(v)` .
` t = sqrt((2 xx 29.6)/(9.8)) + (19.6)/(350) = 2 + 0.056 = 2.056 `sec
Hence the correct choice is (a ).