HELP PLEASEE [IREADY DIAGNOSTIC]
1 answer:
You might be interested in
Answer:
Distance between the surface and source of light will be increased by 6 meters.
Step-by-step explanation:
The illuminance of a surface varies inversely with the square of ts distance from the light source.
Let illuminance of the surface = x lumens per square meter
and distance from a light source = y meter.
Now x ∝
Or [k = proportionality constant]
Now we will find the value of k.
k = xy²
k = 120×(6)²
k = 4320
We have to calculate the distance of the source if illuminance of the surface is 30 lumens per square meter.
y² =
y² = 144
y = √144 = 12 meters
So the source of the light will be shifted away from the surface = 12 - 6 = 6 meters.