A man fires a gun and hears its echo after 5 s.The man moves 310 m towards the hill and fires his gun again.This time if he hears the echo after 3 s, calculate the speed of sound.

Open in App

Solution

Let Distance be equal to 'x'

Then the total distance to travel

= 2x

Time = 5s

Speed = Distance/Time

Speed = 2x/5. eq.1

2nd situation

Distance = x - 310

Total distance = 2(x-310)

= 2x - 620

Time = 3 sec

Speed = (2x - 620)/3. eq.2

From eq.1 and eq.2

2x/5 = (2x-620)/3

6x = 5(2x - 620)

6x = 10x - 3100

4x = 3100

x = 3100/4 = 775

775m is the distance

Speed = 2x/5. from eq.1

= 2(775)/5

= 1550/5

= 310m/s

Suggest Corrections

Similar questions

A man standing in front of a vertical cliff fires a gun and hears the echo after $4$ seconds. He moves $150 m$ towards the cliff and again fires the gun. This time, he hears the echo after $3.6$ seconds. Find the distance of the cliff from his first position.

John fires a gun towards a hill and hears its echo after 5 seconds. He then moves 320 m towards the hill and fires his gun again. This time he hears the echo after 3 seconds. Calculate i) the velocity of sound and ii) distance between the original position of man & the hill.

Join BYJU'S Learning Program