A fruit dropped from the top of a tree of height 200 m high splashes into the water of a pond near the base of the tree. When is the splash heard at the top given that the speed of sound in air is 340 ms^(-1).

A fruit dropped from the top of a tree of height 200 m high splashes i

1.	A fruit dropped from the top of a tree of height 200 m high splashes into the water of a pond near the base of the tree. When is the splash heard at the top given that the speed of sound in air is 340 ms^(-1).
Answer» Solution :Let TOTAL time `t=t_(1) + t_(2)`, where `t_(1)` is the time taken from top to SURFACE of WATER and `t_(2)` is the time taken by SOUND to reach the top. Calculation of `t_(1)`: Using `s= ut_(1) + 1/2at_(1)^(2)` Putting, u=0, a=g `=9.8 m//s^(2)` S= 200 m, we get `200 = 1/2 xx 9.8 xx t_(1)^(2)` `200 = 4.9 xx t^(2), t^(2) = 40.816` t= 6.3887 s. and Calculation of `t_(2)`: Using `V= s/t_(2)`, `t_(2) =s/v =200/340 = 0.588`s. `therefore` Total time `t=t_(1) + t_(2)` =6.3887 + 0.588 = 6.97 s The splash has heard at 6.97 s.