- #1

Mastagamer

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This is the question

Find the intensity of a light source that produces an illumination of 7.50 lux at a distance of 30m from the source.

This what I get but it's wrong

84823

This is the formula

E = Illumination

I = luminous intensity of the source ( in lumens)

r= distance between the source and the illuminated surface.

1 lux = 1lm/m^2

Formula E = I/(4*pi*(r^2)

So I did I = E*(4*pi*(r^2)

I =?

E=7.50

r = 30m

I = 7.50lux*(4*pi*(30m^2)

and got I = 84823

rounded in many different forms and I still get a wrong answer.. Any help would be appreciate it.

and is wrong because the computer practice test tells me but doesn't give me an answer.

Find the intensity of a light source that produces an illumination of 7.50 lux at a distance of 30m from the source.

This what I get but it's wrong

84823

This is the formula

E = Illumination

I = luminous intensity of the source ( in lumens)

r= distance between the source and the illuminated surface.

1 lux = 1lm/m^2

Formula E = I/(4*pi*(r^2)

So I did I = E*(4*pi*(r^2)

I =?

E=7.50

r = 30m

I = 7.50lux*(4*pi*(30m^2)

and got I = 84823

rounded in many different forms and I still get a wrong answer.. Any help would be appreciate it.

and is wrong because the computer practice test tells me but doesn't give me an answer.

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