Final answer:
In the context of physics, to achieve the recommended illuminance of 500 lux for desktop lighting, fixtures initially at 2.50 meters providing 300 lux must be lowered to 1.22 meters. The example provided illustrates the inverse square law, showing the rapid decrease in light levels with increased distance from the source.
Step-by-step explanation:
The subject matter concerns lighting and illumination, which is closely related to the field of physics.
Understanding Illuminance and Its Relation to Distance
To achieve the recommended illuminance of 500 lux for desktop lighting, we apply the inverse square law. The law states that illuminance is inversely proportional to the square of the distance between the light source and the surface. Given that the current height of the lighting fixtures is 2.50 meters and it provides 300 lux, to obtain the desired 500 lux, the lights need to be lowered to 1.22 meters above the desktop.
Moreover, when considering lighting at a greater distance, such as 3 meters, the illuminance significantly decreases to 17.7 lux. This illustrates how promptly light levels drop as the distance from the source increases, which is critical for practical lighting applications both in residential and occupational settings.