Tag: problems on sound

Questions Related to problems on sound

A boy shouts while standing in front of a hill. He hears an echo after 6 sec. If the speed of sound  in air is 340 m/s. What is the distance of the hill from the position of the body?

physics study of sound determination of speed of sound by echo problems on sound sound needs a medium

  1. 519 m

  2. 1020 m

  3. 2040 m

  4. none

Show answer
Correct Option: B
Explanation:

Let distance of hill from the position of the body = d
Echo is heard after 6 sec
$d = v \dfrac{t}{2}$
$= \dfrac{(340 \times 6)}{2}$
$= 1020 m$

A sonar echo takes 8.8 s to return from a shack. How far away is the shack?

Given speed of sound in sea-water = 1533 m/s

physics study of sound determination of speed of sound by echo problems on sound sound needs a medium

  1. 348 m

  2. 5720 m

  3. 6745 m

  4. 13490 m

Show answer
Correct Option: D
Explanation:

Let $d$ be the distance of shack from the sonar . Therefore  distance covered by sound to come back to sonar after reflection from shack ,  $=d$ ,

given , speed of sound in sea water $v=1533m/s  ,  t=8.8s$ ,
we have , distance=speed$\times time$ ,
               $d=v\times t=1533\times8.8$ ,
or            $d=13490.4m$