Question

What is the ratio of the intensities of an earthquake P wave passing through the Earth and detected at two points 14 km and 49 km from the source?

Answer 1

`(I_1)/(I_2)=12.25`

Step-by-step explanation:

`r_1` = 14 km

`r_2` = 49 km

Intensity of a wave is inversely proportional to distance

`I\propto (1)/(r^2)`

So,

`(I_1)/(I_2)=(r_2^2)/(r_1^2)\\\Rightarrow (I_1)/(I_2)=(49^2)/(14^2)\\\Rightarrow (I_1)/(I_2)=12.25`

The ratio of the intensities is
`(I_1)/(I_2)=12.25`