Question

Radiationâ machines, used to treatâ tumors, produce an intensity of radiation that varies inversely as the square of the distance from the machine. At 3â meters, the radiation intensity is 62.5 milliroentgens per hour. What is the intensity at a distance of 2.82.8 âmeters?

Answer 1

71.75 milliroentgens per hour

Explanation:

The intensity(I) of Radiation varies inversely as the square of the distance (D) from the machine.

This is written as:

`I \propto (1)/(D^2) \\$Introducing the constant of Variation k$\\I = (k)/(D^2) \\$When D=3 meters, I=62.5 milliroentgens per hour$\\62.5= (k)/(3^2)\\k=62.5 X 9 =562.5\\$Substituting K=562.5 into the variation equation$\\I = (562.5)/(D^2) \\$Therefore, When D=2.8 meters$\\Intensity,I = (562.5)/(2.8^2)=$71.75 milliroentgens per hour$`