Chapter 24, Problem 87A

Interpretation Introduction

Interpretation:

To ensure safety of workers from gamma rays while monitoring thickness of sheet safe, distance from gamma rays is to be estimated.

Concept introduction:

In a nuclear reaction, unstable nuclide disintegrates into stable nuclide with emission of various radiations spontaneously. It is called radioactivity of nucleus. Emission of rays like alpha, beta and gamma rays occur in the process which changes the identity of nucleus.

During a nuclear change, an element undergoes change in its atomic mass or atomic number or both by emission of charged particles such as beta particle, alpha particle. Beta particle is one that has unit negative charge and alpha particle is one that has 2 unit positive charges and is equivalent to helium atom ${}_2^4\text{He}$. Emission of proton, beta particle, alpha particle causes a change in atomic number of element.

Answer to Problem 87A

The formula that relates intensity and distance is as follows:

$I_1{d}_1^2=I_2{d}_2^2$

Where,

$d_1$ and $d_2$ are two distances from source.

$I_1$ and $I_2$ are the intensities of radiation at distance $d_1$ and $d_2$, respectively.

So to ensure safety of workers from gamma rays while monitoring thickness of sheet, intensity of rays as per distance must be calculated using above formula.

Explanation of Solution

People working near to radioactive sources are needed to carry out various safety measures which includes knowing the correct radiation dosage of the nuclear rays.

Radiation dose is the amount of radiation body absorbs on being exposed to radioactive rays. This is measured in unit, the red and the rem. Intensity of any radiation depends on the distance of source. Higher the distance, lower the intensity.

The formula that relates intensity and distance is as follows:

$I_1{d}_1^2=I_2{d}_2^2$

Where,

$d_1$ and $d_2$ are two distances from source.

$I_1$ and $I_2$ are the intensities of radiation at distance $d_1$ and $d_2$, respectively.

So to ensure safety of workers from gamma rays while monitoring thickness of sheet, intensity of rays as per distance must be calculated using above formula.

Conclusion

The formula that relates intensity and distance is as follows:

$I_1{d}_1^2=I_2{d}_2^2$

Where,

$d_1$ and $d_2$ are two distances from source.

$I_1$ and $I_2$ are the intensities of radiation at distance $d_1$ and $d_2$, respectively.

So to ensure safety of workers from gamma rays while monitoring thickness of sheet, intensity of rays as per distance must be calculated using above formula.