A stone is dropped into a well and the sound of splash is heard after 5.3sec. If the water is at a depth of 122.5m from the ground, the velocity of sound in air is

A stone is dropped into a well and the sound of splash is heard after

1.	A stone is dropped into a well and the sound of splash is heard after 5.3sec. If the water is at a depth of 122.5m from the ground, the velocity of sound in air is
Answer» Solution :If `t_(1)` is the time taken by stone to REACH the GROUND and `t_(2)` the time taken by sound to go up, then `t_(1)+t_(2)=5.33` SINCE `s=ut+(1)/(2)at^(2) 122.5=0t+(1)/(2)xx9.8xxt_(1)^(2)` `THEREFORE t_(1)^(2)=(245)/(9.8)=(2450)/(98)=25 therefore t_(1)=5s therefore t_(2)=0.33s` Velocity of sound = `therefore t_(1)^(2)=(245)/(9.8)=(2450)/(98)=25 therefore t_(1)=5s therefore t_(2)=0.33s`