In the video, I show measurements of light intensity (measured in lux) from a flashlight at several distances. With the light off, the ambient room light was 198 lux. At 10 cm, the light sensor read 2737 lux. Unfortunately, the flashlight flickered at 20 cm and the reading wasn't accurate.
Physics tells us that light intensity varies inversely with the square of the distance, or in other words, it should follow the equation L = k/x^2 + L_"ambient"
L is the light intensity, in lux
k is some constant
x is the distance from the light to the sensor
Lambient is the ambient room light, in lux
Using the given data, complete the equation for light intensity in terms of distance, x.
Use your equation to predict what the light measurement at 20cm should have been, to the nearest lux.
If we wanted a light intensity of 1700 lux, at what distance should we place the light. Give your answer to at least 1 decimal place.
