A skyrocket explodes 78 m above the ground. Three observers are spaced 70 m apart, with observer A directly under the point of the explosion. A B C 78 m 70 m 70 m Find the ratio of the sound intensity heard by observer A to that heard by observer B. For practical purposes, you may treat each observer as a point on the ground.

The ratio is          

Explanation:

From the question we are told that

   The position of the explosion from the ground  is  

   The distance of separation between the observers is  

Generally the intensity of sound varies inversely with the square distance from the source of the sound i.e  

Here k  is a constant , so  

=>            

   Now given that observer A is directly under the explosion , the his distance from the sound is      

  The distance of observer B from the explosion is  

   while  the distance of observer C from the explosion is  

Generally the ratio of the sound intensity heard by observer A to that heard by observer B is mathematically represented as

=>    

=>            

option number c is the right answer.