Trying to Determine if Proper Illumination is Provided

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In summary, the conversation discusses a problem involving determining the amount of illumination in a given space using a specific equation. The units for the distance are in feet and the units for the illumination results are ft-candles (lux). The goal is to meet the requirement of having an initial illumination of at least 1 ft-candle (10.8 lux) and a minimum of 0.1 ft-candle (1.1 lux) measured along the path of egress at floor level. The attempted solution involved multiplying 4 x pi x distance (ft) but the correct method would be to use the squared operator (^2). The final result should be in ft-candles.
  • #1
Shag-X
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Homework Statement



Can someone help me solve the following? I trying to determine how much illumination is applied to a given space based on the following equation. I have no math solving abilities whatsoever.

Homework Equations



Where c = 5.4 watts

Where ft = Problem 1: 22; Problem 2: 27; Problem 3: 30

(c) / (4*π*distance (ft) ^2)


The Attempt at a Solution



Tried to use a science calculator - Multiplied 4 x pi x the distance. Couldn't figure out how to multiply in the caret 2.
 
Last edited:
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  • #2
Shag-X said:

Homework Statement



Can someone help me solve the following? I trying to determine how much illumination is applied to a given space based on the following equation. I have no math solving abilities whatsoever.

Homework Equations



Where c = 5.4 watts

Where ft = Problem 1: 22; Problem 2: 27; Problem 3: 30

(c) / (4*π*distance (ft) ^2)


The Attempt at a Solution



Tried to use a science calculator - Multiplied 4 x pi x the distance. Couldn't figure out how to multiply in the caret 2.

Welcome to the PF.

First, you need to be careful to work in consistent systems of units. When you typed distance (ft), is that meant to say that the units of the distance are in feet? Farther up in the problem you assigned values to "(ft)", which doesn't make sense if that's just the units of "distance".

And what are the units of the 3 distances? Feet? Like:

1) distance = 22 feet
2) distance = 27 feet
3) distance = 30 feet

And do you know what the units are for the illumination results that you are trying to calculate? The way the equation is set up now (assuming I've interpreted your use of "(ft)" right), you would get a result in Watts/Square Feet.

And finally, the "^2" is not something you multiply by. It represents the "squared" operator. Like, 10^2 = 10*10 = 100.
 
  • #3
1. When you typed distance (ft), is that meant to say that the units of the distance are in feet?

Answer 1: Yes. (ft) is the distance, in feet, that the area to be illuminated is from the light
source.

2. What are the units of the 3 distances?

Answer 2: Yes. The units of the three distances are feet. The area is a gradually riser theater
floor, with aisles that are required to be illuminated along their entire length.

3. What are the units for the illumination results?

Answer 3: The units for the illumination results are ft-candle (lux).

Here is the requirement:

Emergency lighting facilities shall be arranged to provide initial illumination that is not less than
an average of 1 ft-candle (10.8 lux) and, at any point, not less than 0.1 ft-candle (1.1 lux),
measured along the path of egress at floor level.

Made an attempt at solving and came up with - .00088785. But, I don't think that correct.

Thank you,
 
Last edited:
  • #4
Shag-X said:
1. When you typed distance (ft), is that meant to say that the units of the distance are in feet?

Answer 1: Yes. (ft) is the distance, in feet, that the area to be illuminated is from the light
source.

2. What are the units of the 3 distances?

Answer 2: Yes. The units of the three distances are feet. The area is a gradually riser theater
floor, with aisles that are required to be illuminated along their entire length.

3. What are the units for the illumination results?

Answer 3: The units for the illumination results are ft-candle (lux).

Here is the requirement:

Emergency lighting facilities shall be arranged to provide initial illumination that is not less than
an average of 1 ft-candle (10.8 lux) and, at any point, not less than 0.1 ft-candle (1.1 lux),
measured along the path of egress at floor level.

Made an attempt at solving and came up with - .00088785. But, I don't think that correct.

Thank you,

How does one convert from Watts per square foot to ft-candles?
 
  • #5


I would first clarify the question by asking for more information about the given space and what type of illumination is being referred to (natural or artificial). I would also ask for the specific units of measurement for the distance (feet, meters, etc.) and for any other relevant variables that may affect the calculation.

Next, I would suggest using the given equation to calculate the amount of illumination. This equation is known as the Inverse Square Law and is commonly used to determine the intensity of light at a certain distance from its source.

To solve the equation, I would first plug in the given value for c (5.4 watts) and then multiply it by 4 and pi. The distance value should be converted to meters before being squared. Depending on the units of measurement, this may require converting from feet to meters or vice versa. Once the values are plugged in, simply solve for the final answer.

If the attempt at a solution involved using a scientific calculator, I would suggest breaking down the equation into smaller parts and solving them separately. For example, first calculate 4 x pi and then multiply that value by the distance squared. Finally, divide the result by c (5.4 watts) to get the final answer.

In conclusion, with the given equation and the necessary information, it is possible to determine the amount of illumination provided in a given space. It is important to clarify the question and use the correct units of measurement to get an accurate result.
 

1. What is the importance of proper illumination?

Proper illumination is essential for performing accurate scientific experiments and observations. It allows for better visibility and clarity, which is crucial for obtaining reliable data and results.

2. How do you determine if proper illumination is provided?

There are various ways to determine if proper illumination is provided, including measuring the light intensity with a light meter, assessing the color temperature, and examining the light distribution in the workspace.

3. What are the consequences of inadequate illumination?

Inadequate illumination can lead to incorrect observations, inaccurate data, and potential safety hazards. It can also cause eye strain and fatigue, which can impact the quality and efficiency of scientific work.

4. How can proper illumination be achieved?

Proper illumination can be achieved by using appropriate lighting fixtures, such as adjustable desk lamps or overhead lights, and positioning them at the correct angle and distance. It is also crucial to consider the type of work being done and the specific lighting requirements for each task.

5. Can lighting affect scientific results?

Yes, lighting can significantly impact scientific results. Improper illumination can lead to distorted images, misinterpreted data, and inaccurate conclusions. Therefore, it is essential to ensure proper illumination when conducting scientific experiments or observations.

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