Question

The the intensity I of light (in lumens) in a certain lake at a depth of x feet is given by log(1/12) = -0.00235x. What is the intensity of the light (in lumens) at a depth of 20 feet? Round your answer to the nearest hundredth and label 1 your answer.​

Answer 1

11.45 lumens

Explanation:

We are given that

`log(I/12)=-0.00235x`

Where x=Depth

I=Intensity of light

We have to find the intensity of the light at a depth of 20 feet.

Substitute the value of x

`log(I/12)=-0.00235* 20`

`log(I/12)=-0.047`

`(I)/(12)=e^(-0.047)`

`I=12e^(-0.047)`

`I=11.45 Lumens`

Hence, the intensity of the light (in lumens) at a depth of 20 feet=11.45 lumens