Q1. A person standing between two hills hears the echo in 1 sec. and 2sec . if the speed of sound wave 340m/sec . then find the distance between two hills?

let the distance between the source and the first mountain be x.

2x=velocityxtime

x=340x1/2

 =170m

let the distance between the source and the second mountain be y

2y=velocityxtime

y=340x2/2

 =340m

the distance between the 2 mountain is x+y=170+340

  =510m