Radiation from a point source follows an inverse square law. If a Geiger counter that is 1 m away from the sma

Radiation from a point source follows an inverse square law. If a Geiger counter that is 1 m away from the small source reads 700 counts per minute, what will be its reading 3 m away from the source?Radiation from a point source follows an inverse square law. If a Geiger counter that is 1 m away from the sma
It is quite easy to solve this problem

Using inverse square law's rule,which is

S1.R1^2 = S2.R2^2



Then substitute all the values

(700cpm) [(1m)^2] = S2 [(3m)^2]

S2 = 700 / 9

= 77. 777777777777778 cpmRadiation from a point source follows an inverse square law. If a Geiger counter that is 1 m away from the sma
Detector is 3 x further away so presumably count rate will be reduced to 1/3^2 or 1/9 of its value.

700/9 or about 78 cpm