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 122.5 m 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 122.5 m 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 xx 9.8 xx t_(1)^(2)` `t_(1)^(2)=(245)/(9.8)=(2450)/(98)=25""therefore t_(1)=5s` `t_(2)=0.33s` Velocity of sound `=("displacement")/("time")=(122.5)/(0.33)=367m//s`