If an exposure rate of 15 R/min is measured at a distance of 3 meters, what will be the exposure rate at 2 meters?

To determine the exposure rate at a different distance from the source, the inverse square law of radiation can be applied. This law states that the intensity of radiation (or exposure rate) is inversely proportional to the square of the distance from the source of radiation. Mathematically, this can be expressed as:

[ I_1 \cdot D_1^2 = I_2 \cdot D_2^2 ]

Where:

• ( I_1 ) is the initial exposure rate,

• ( D_1 ) is the initial distance,

• ( I_2 ) is the new exposure rate,

• ( D_2 ) is the new distance.

In this scenario, the initial exposure rate is 15 R/min at a distance of 3 meters, and we want to find out the exposure rate at a distance of 2 meters.

Using the formula, we set it up as follows:

[ 15 , \text{R/min} \cdot (3 , \text{m})^2 = I_2 \cdot (2 , \text{m})^2 ]

Calculating the squares gives:

[ 15 \cdot 9 = I