Light intensity (I) is proportional (a) to the inverse square of distance (d) of a subject from a light
source. The relationship in intensities for subjects at different distances from the same source can
be likewise seen as a ratio or proportional relationship.
I x
A proportional relationship can be mathematically expressed as follows for light intensity (I) in
lumens when a subject is at the light source.
Lumens at current distance
Lumens at origin or source
So, if a light intensity (I) is 516 lumens at the source and 4 lumens at a specific distance from the
source, what is that distance?
Round the value to the nearest tenth if necessary. You do not need to include a label for distance.
Only the number, rounded to the tenth, will be necessary.

Answers

Answer 1

The required distance is 11.4 rounded to the tenth

If light intensity (I) is proportional (a) to the inverse square of distance (d) of a subject from a light  source, this is expressed as:

l = ka/dk is the variation constant

If a light intensity (I) is 516 lumens at the source and 4 lumens at a specific distance from the  source, the distance is calculated as:

l = a/d²

d² = a/l

d² = 516/4

d = √129

d = 11.4

Hence the required distance is 11.4 rounded to the tenth

Learn more on inverse variation here:https://brainly.com/question/13998680


Related Questions

The sum of twice a number and 5 is 25

Answers

Answer:

If the directions say write an equation: 2n + 5 =25

If the directions say also to solve the equation and find the number: 10

Step-by-step explanation:

"The sum" means we're using adding. So what things are we adding together? The question says "twice a number" and 5. Well we've got the 5. And "twice" means two times. And "a number" means we don't know the number yet, so we choose a variable, like n.

"Twice a number" can be written 2n.

So far we have:

2n + 5 is 25

We use = for the "is" in this sentence.

2n + 5 = 25

Now we can solve it.

Subtract 5 from both sides.

2n = 20

Divide by 2 on both sides.

2n/2 = 20/2

n = 10

The number is 10.


(ii) Kolyan has $9 to spend.
Work out the total amount Kolyan spends on water and biscuits as a fraction of the $9.
Give your answer in its lowest terms.

Answers

The amount spent on water and biscuits is $5.4 and $3.6, respectively

From the question, the ratio is given as:

[tex]Biscuits : Water= 3 : 2[/tex]

Represent both proportion as a fraction

[tex]Biscuits = \frac 35[/tex]

[tex]Water= \frac 25[/tex]

Kolyhan has $9.

So, the amount spent on biscuit is:

[tex]Biscuit= \frac 25 \times 9[/tex]

[tex]Biscuit= 3.6[/tex]

The amount spent on water is:

[tex]Water = 9 - 3.6[/tex]

[tex]Water = 5.4[/tex]

Hence, the amount spent on water and biscuits is $5.4 and $3.6, respectively

Read more about ratios and proportions at:

https://brainly.com/question/18170686

Please help I forgot how to do this completely

Answers

Step-by-step explanation:

9x+79+56=180(sum of angles of triangle)

9x+135=180

9x=180-135

x=45÷9

x=5

HELP HURRY PLS

What is the equation of this line?
A. y= 3/2x -2
B. y=2x+2/3
C. y=2/3x-2
D. y= -2x+3/2

Answers

Answer:

The answer is C, y = 2/3x -2

Step-by-step explanation:

Use the rise over run strategy on linear functions such as this one

Which ordered pairs are solutions to the inequality 2y-x≤-6 ?
a. (0,-3) b. (5,10) c. (2, -2) d. (-5, 2)

Answers

Answer:

C

Step-by-step explanation:

does (0,0) make the equation y = x true​

Answers

True because its true maybe but just answer true

PLEASE HELP!!! WILL GIVE BRAINLIEST!!!!

Answers

3. identity property of addition
7. associative property of addition
8. multiplicative property of zero

Explanation of approximation, decimal place, significant figure

Answers

Answer:

im not an expert in math but i'll do my best:

1. an approximation is something that is almost, but not exactly something. for example, 5.02 is approximately 5. it's not EXACTLY 5, but it's around 5.

2. decimal place refers to the position of numbers after the decimal point. let's take the decimal number 7.89 for example. there are 2 numbers after the decimal point, which is 8 and 9. hence we say that 7.89 has 2 decimal places.

3. significant figure is kind of hard to explain, so i'll jump into the example straight away.

5.874 to 3 significant figures is 5.87. what i did was count 3 digits: starting from 5 to 7. to round to 3 significant figures, i look at the 4th digit, which is 4 in this case. if it's smaller than 5, i ignore everything past the digit 7, and leave the final answer as 5.87.

if the 4th digit is greater than or equal to 5, i add 1 to the 3rd digit THEN leave out all the numbers after the 3rd digit. (if this were the case, the answer would be 5.88)

lets take a trickier example, 0.064591

in this case i cannot start counting 3 digits starting from 0. i have to count starting from the number 6. the concept in this case is that the 1st significant figure cannot be a 0. in this case the answer to 3 significant figures would be 0.0646.

however, 0 can be a significant figure if it's after another number. for instance 0.90672

the 0 after the 9 would count as a significant figure because it's not the 1st significant figure in the number. however the 0 before the 9 would NOT count as one because 0 cannot be the 1st significant figure. the answer to 3 significant figures would be 0.907.

sorry this was so lengthy, i just hope this answers your question on what these are and how they work. good luck!

Use <, >, or = to make the
statement true.
20[?]-1

Answers

Answer:

20 > -1

Step-by-step explanation:

Well 20 is a positive integer that is 20 units from 0 whereas -1 is a negative integer that is 1 unit behind zero.

PLEASE HELP!!
This is worth 20 points please help me!

Answers

If it’s worth 20 why you just giving 5 points boo

Your little brother wants hot chocolate ot be 150 degrees, but you accidentally heated the water to 175 degrees. If after 5 minutes the temperature is 165 and the temperature in your house is 70 degrees, how long will your little brother have to wait to drink his hot chocolate?

Answers

Answer:

12.5 minutes

Step-by-step explanation:

it takes 5 minutes to cool 10 degrees

after ten minutes it would be 20 degrees less

then after 2.5 minutes it would be 5 degrees less

so it would take you 12.5 minutes to get 25 degrees less

Answer:My little brother will have to wait for 12.5 minutes to drink his hot chocolate.Step-by-step explanation:

We know that in 5 minutes, the temperature of the hot chocolate decreased by 10 degrees. We also know that the temperature is fixed at 70 degrees. Now, using the info given, let's solve!

=> 5 minutes = 10 degrees decrease=> 1 minute = 2 degrees decrease=> 1 minute x 12.5 = 2 x 12.5 degrees decrease=> 12.5 minutes = 25 degrees decreaseConclusion:

Therefore, my little brother will have to wait for 12.5 minutes to drink his hot chocolate.

Hoped this helped.

[tex]BrainiacUser1357[/tex]

A. A cylindrical barrel has diameter 14 m and height 9 m. Find the cost of painting the inner side of the barrel at 132 per m? (Take = 3.14.)​

Answers

Answer:

Here is your Answer

Step-by-step explanation:

DIAMETER = 14 M

RADIUS = DIAMETER ×0.5

RADIUS = 14÷0.5 = 7

HEIGHT = 9M

AREA OF CYLINDER = 2pi*R* H

AREA = (2× 3.14×7×9) M^2

AREA =395.64 M^2

COST FOR AREA M^2 = ₹ 32

COST FOR AREA 395.64 =₹(395.64×32)

SO, ANSWERS= ₹ 12660.48

Plz Mark Me As Brainiest

Answer:

$ 12660.5

Step-by-step explanation:

We know that

Radius = Diameter/2

Radius = 14/2 = 7 m

Now,

CSA of cylinder = 2πrh

=> 2 × 3.14 × 7 × 9

=> 395.6 m²

Now,

Cost = 395.6 × 132

=> $ 12660.5

Identify the slope represented in the graph below.

Answers

Answer:
The slope is -2
Explanation:
I choose two points on the graph (0,-2) and (-1,0) and put it into the slope form using two coordinate pairs which is y-y/x-x and got -2/1 which simplifies down to -2

Determine the intercepts of the line.

Answers

Answer:

y-intercept: (0,5)

x-intercept: (5/2,0)

Step-by-step explanation:

[tex]-4x+7=2y-3[/tex]

[tex]-4(0)+7=2y-3[/tex]

[tex]0+7=2y-3[/tex]

[tex]7=2y-3[/tex]

[tex]10=2y[/tex]

[tex]5=y[/tex] <-- y-intercept: (0,5)

[tex]-4x+7=2y-3[/tex]

[tex]-4x+7=2(0)-3[/tex]

[tex]-4x+7=-3[/tex]

[tex]-4x=-10[/tex]

[tex]x=\frac{5}{2}[/tex] <-- x-intercept: (5/2,0)

Can somebody help me :

Answers

Answer:

A

Step-by-step explanation:

Negative numbers are smaller than positive numbers.

Answer:

Your correct 6.55 is a positive number while -6.5 is negitive and positive numbers are always larger then negitive ones

Hope This Helps!!!

See attachment for question

Answers

I can’t see the attachment?

HELP PLEASE!!!!!!!!!!!!

Answers

The answer to this question would be B.35

Neika is saving her money to buy a DVD that costs $45. If she has a job that pays $8 per hour, write and solve an inequality that shows the minimum number of hours that Neika will need to work in order to pay for the DVD.​

Answers

Answer:

8x6=48 so in 6 hours she will have enough money to buy it

Step-by-step explanation:

6 hours will give her 48 dollars if the dvd costs 45 so she will have to work 6 hours

Simple: get the Equation PART 2!!

Answers

The answer is N•17=C

A mosquito flies at a speed of 40.2 meters per minute.

At this rate, how many meters can it fly in 5 minutes?

PLZ HELP

Answers

Answer:

201

Step-by-step explanation:

40.2*5=201

201 meters per minute

the least common multiple of 9 and 42 through prime factorization?

Answers

Answer:

3

Step-by-step explanation:

9= 3*3

42=3*7*2

How is 6% expressed as a fraction in lowest terms

Answers

6% expressed as a fraction in lowest terms is 3/5

Can any one explain this question worth points! plz explain if you can

Answers

Answer:

x = 31

Step-by-step explanation:

The given angles are supplementary and their sum is 180 degrees

5x - 16 + x + 10 = 180 add like terms

6x - 6 = 180 add 6 to both sides

6x = 186 divide both sides by 6

x = 31

For health reasons, Amir wants to drink eight
glasses of water a day. He's already had six
glasses. What fraction of eight glasses does
Amir have left to drink?
A. 1/8
B.1/6
C. 1/4
D.1/3

Answers

Answer is C, 1/4 left to drink. 6/8 reduces to 3/4, so 3/4 + 1/4 = 1 whole, or 8/8

A system of equations is shown: 2x = â’y 6 â’4x 3y = 8 What is the solution to this system of equations? (â’1, â’4) (1, 4) (4, 1) (â’4, â’1).

Answers

The correct option is B. (1,4).

Given equations,

[tex]2x=-y+6....(1)\\-4x+3y=8....(2)[/tex]

We have to find the solution of the given system of equations.

Equation 2 can be written as,

[tex]-2\times(2x)+3y=8\\[/tex]

Now by substitution method, putting the value of [tex]2x[/tex] from Equation (1) in above equation, we get

[tex]-2\times(-y+6)+3y=8\\2y-12+3y=8\\5y-12=8\\5y=20\\y=4[/tex]

Now putting the value of y in equation 1 we get,

[tex]2x=-4+6\\2x=2\\x=1[/tex]

Hence the solution of the given system of equation will be (1,4).

For more details follow the link:

https://brainly.com/question/12824145

A line includes the points (3, 7) and (14, 18). What is its equation in slope-intercept form?

Answers

Answer:

y=x+4

Step-by-step explanation:

A laptop is 30% off the regular price of 920$ If a 6% sales tax is added to the cost what is total cost of the laptop

Answers

Answer

If we had a sale price of 30% off of $1,050then the sale price is 70% of $1,050 or 0.7(1050) Then we add 7% sales tax to that making thefinal price paid 107% of [0.7(1050)] ... 1.07[0.7(1050)] = $786.45



Help plzz I don’t get it

Answers

x intercept The x intercept is the point where the line crosses the x axis. At this point y = 0.

Good morning fellow Brainaics.

Please help me with this question.

Answers

Answer:

Veganism :)

Step-by-step explanation:

Step-by-step explanation:

B: Veganism.

but ... how is that mathematics ?

What is the factored form of n^3+512 (please answer) picture provided

Answers

[tex] {n}^{3} + 512 \\ = {(n)}^{3} + {(8)}^{3} \\ by \: using \: {a}^{3} + {b}^{3} = (a + b)( {a}^{2} - ab + {b}^{2}) we \: \: \: get \\ = (n + 8)( {(n)}^{2} - n \times 8 + {(8)}^{2} ) \\ = (n + 8)( {n}^{2} - 8n + 64)[/tex]

Hope you could get an idea from here.

Doubt clarification - use comment section.

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