Final answer:
To find the correct exposure time for an SFD (Source-to-Film Distance) of 16 inches, we can use the concept of the inverse square law. The correct exposure time would be 4 seconds.
Step-by-step explanation:
To find the correct exposure time for an SFD (Source-to-Film Distance) of 16 inches, we can use the concept of the inverse square law. The inverse square law states that the intensity of radiation is inversely proportional to the square of the distance from the source.
In this case, we have an SFD of 8 inches with an exposure time of 1 second, which produces a satisfactory radiograph. To find the correct exposure time for an SFD of 16 inches, we can set up a proportion:
Exposure time (8 inches) / Exposure time (16 inches) = (Distance (16 inches))^2 / (Distance (8 inches))^2
Simplifying this equation, we can solve for the correct exposure time:
Exposure time (16 inches) = 4 * Exposure time (8 inches)
Therefore, the correct exposure time for an SFD of 16 inches would be 4 seconds.