A technologist standing 3 feet from a fluoroscopic table increases their distance to 7 feet. What is the new dose rate if the original was 20 microgray/hour?

To understand how distance affects the dose rate, it's important to apply the inverse square law, which states that the intensity of radiation (or dose rate) is inversely proportional to the square of the distance from the source. This means that as you move away from a radiation source, the dose rate decreases significantly.

Initially, the technologist is standing 3 feet from the fluoroscopic table, where the dose rate is measured at 20 microgray/hour. When the distance is increased to 7 feet, we can find the new dose rate using the inverse square law formula:

[

\text{New Dose Rate} = \text{Original Dose Rate} \times \left(\frac{\text{Original Distance}}{\text{New Distance}}\right)^2

]

Substituting the values into the formula:

[

\text{New Dose Rate} = 20 , \text{microgray/hour} \times \left(\frac{3 , \text{feet}}{7 , \text{feet}}\right)^2

]

[

= 20 , \text{microgray/hour} \times \left(\frac{9}{49}\right)

]

[

= 20