Please help, I am desperate!?! Will name Brainliest!!

Suppose that a spotlight is used for lighting objects at many different distances and that the area A of the light circle produced is related to the distance x to the lighted object by A=0.1x^2.

a. If the spotlight produces 250 lumens of light energy, what function gives the intensity of the light I, (in lumens per square foot) as a function of the distance x in feet from the spotlight to its target?

b. Write and solve equations that match these questions about the light intensity from the spotlight.

i. What is the intensity of light on an object that is 20 feet from the spotlight source?

ii. How far from the spotlight is an object that recieves 100 lumens of light per square foot?

Answers

Answer 1

Answer:

Intensity = 2500/x^2

6.25 lumem

5 Feets

Step-by-step explanation:

Given the following :

Area (A) = 0.1x^2

Intensity, Energy and Area are related by the formular :

Intensity = power / Area

A) If 250 lumens of light energy is produced :

Intensity (I) = 250 / 0.1x^2

Intensity = 2500/x^2

x = distance

B) USING THE EQUATION :

1) What is the intensity of light on an object that is 20 feet from the spotlight source?

x = 20

Intensity = 2500/x^2

Intensity = 2500/20^2

Intensity = 2500/400

Intensity = 6.25 lumen

11) How far from the spotlight is an object that recieves 100 lumens of light per square foot?

Intensity = 100

100 = 2500 / x^2

100x^2 = 2500

x^2 = 2500/ 100

x^2 = 25

x = 5 Feets


Related Questions

Each table below lists the squared residuals for a line of fit for a certain set of data points. Find the sum of the squared residuals for each potential line of fit, and then determine which potential line is the true line of best fit.

c.) Square of Residual
.200
.116
.16

D) Square of Residual
.0036
.0016
.009​

Answers

Answer:

c

Step-by-step explanation:

0.07 is 10 times as great as ? A.0.1 B.0.7 C.0.001 D.0.007

Answers

Answer:

D. 0.007

Step-by-step Explanation:

0.07= 10 x

= 0.07/ 10

= 0.007

26.9 microgram/milliliter to hectograms/deciliter

Answers

Answer:

.0000269 hectograms/ deciliter

2.69 * 10^e-5 hectograms/ deciliter

Step-by-step explanation:

micro grams to hectograms

10^8 micrograms = 1 hectogram

milliliters to deciliter

100 milliliters = 1 deciliter

Using conversion factors

26.9 microgram         1 hectogram           100 milliliters

----------------------- * ---------------------------  * ---------------------

milliliter                     10^8 micrograms           1 deciliter

2690 hectograms

---------------------------

10^8 deciliters

.0000269 hectograms/ deciliter

2.69 * 10^e-5 hectograms/ deciliter

Jacob spent $35.40 to fill up 15 gallons of gas in his pick-up truck. How much does 6 gallons cost?

Answers

Answer:

$14.16 for 6 gallons.

Step-by-step explanation:

35.40/15 = 2.36

2.36*6 = 14.16

Need help! With both, please please help!

Answers

CD is 120 and should be 90

In the accompanying diagram, a right circular cone is carved out of a solid foam cylinder and discarded. What is the volume of the foam remaining in the cylinder?
A. 150π cubic units
B. 125π cubic units
C. 100π cubic units
D. 50π cubic units

Answers

Answer:

100π cubic units is left

Step-by-step explanation:

πr²h - 1/3πr²h

π(5)²(6) - 1/3π(5)²(6)

150π - 50π = 100π

The volume of the foam is 100π cubic units remaining in the cylinder.

Given,

Radius of cone (r) = 5

Height of cone (h) = 6

What is the volume of a cone?

The volume of a cone is defined as the amount of space occupied by a cone in a three-dimensional plane.

∵ The volume of the cone (V )= 1/3πhr²

To determine the volume of the foam remaining in the cylinder

Subtract the volume of the cone into the volume of the cylinder

⇒ πr²h - 1/3πr²h

Substitute the values of h and r,

⇒ π(5)²(6) - 1/3π(5)²(6)

⇒ 150π - 50π

⇒ 100π

Hence, The volume of the foam is 100π cubic units remaining in the cylinder.

Learn more about the volume of the cone here:

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A store reduces the price of a jacket by 40%. The sale price of the jacket is marked as $30. What percent of the original price is the sale price? What was the original price of a jacket?

Answers

Answer:

-60%

-$50

Step-by-step explanation:

As the statement says that the price of the jacket was reduced by 40%, to determine the percent that the sale price represents from the original price, you have to subtract 40% from 100% that represents the original price:

100%-40%= 60%

This means that $30 represents 60% of the original price.

-To determine the original price of the jacket, you can use the rule of three:

$30 →  60%

 x    ←  100%

x=(100*30)/60= 50

According to this, the original price of a jacket was $50.

is -7 a rational number

Answers

Yes it is a rational number because it can also be written as a fraction.

Hello I was wondering if you can help me list these from least to greatest ​

Answers

Answer:

See  below.

Step-by-step explanation:

Convert to decimal form

7 3/5 = 7.6

7 7/10 = 7.7

10 2/5 = 10.4

8 1/2 = 8.5

So the answer is

7 3/5 , 7 7/10, 8.3, 8.1/2, 10.2  10 2/5, 11.1.

The upper-left coordinates on a rectangle are (-1, 4), and the upper-right coordinates are (3, 4). The rectangle has a perimeter of 24 units. Draw The rectangle on the coordinate plane below.

Answers

Answer:

Please refer to the attached diagram for answer.

Step-by-step explanation:

Upper-left coordinates on a rectangle are (-1, 4)

Upper-right coordinates are (3, 4)

Perimeter of rectangle = 24 units

To find:

To draw the rectangle on the coordinate plane.

Solution:

Let the rectangle be ABCD.

So, sides AB  = CD and BC = DA

Let Point A has coordinates (-1, 4).

And upper right coordinates will be adjacent to A.

So, let Point B (3, 4).

Let us find the distance between A and B by distance formula:

[tex]D = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

Where,

[tex]x_2 = 3\\x_1 = -1\\y_2 = 4\\y_1 = 4[/tex]

[tex]AB = \sqrt{(3-(-1))^2+(4-4)^2}\\\Rightarrow AB = \sqrt{(4)^2+(0)^2}\\\Rightarrow AB = 4[/tex]

AB = 4 = CD

Perimeter of rectangle = Sum of all four sides = 2 (AB+DA) = 24

[tex]2 \times 4 + 2DA = 24\\\Rightarrow 2DA=24-8\\\Rightarrow 2DA=16\\\Rightarrow DA =8\ units[/tex]

As it is a rectangle, its adjacent sides will be perpendicular to each other.

When we move from A to B only x coordinate is changing and it has changed by  4 (3- (-1) ) units. (Found by subtracting the x coordinates of the two points.)

Similarly, when we will move from D to A, only y coordinate will change by 8 units. (D is lower left coordinate so add 8 to y)

[tex]\Rightarrow y + 8 = 4 \Rightarrow y =-4[/tex]

[tex]x[/tex] coordinate will be same as that of A i.e. -1.

So, D will be (-1, -4)

Similarly, when we will move from C to B, only y coordinate will change by 8 units. (C is lower right coordinate so add 8 to y)

[tex]\Rightarrow y + 8 = 4 \Rightarrow y =-4[/tex]

[tex]x[/tex] coordinate will be same as that of B i.e. 3.

So, C will be (3, -4).

Now, let us draw

A(-1, 4)

B(3, 4)

C (3, -4)

D(-1, -4)

Please refer to the attached diagram for answer.

Answer:

A(-1, 4) B(3, 4)C (3, -4)D(-1, -4)

Step-by-step explanation: Brainliest plus-size

The sum of a number and its square is 42. Which equation can be used to find the two numbers for which this is
true?
x2 + x = 42
x2 + 2x = 42
x²+x+42=0
x² + 2x + 42=0

Answers

Answer:

x2 + x = 42

Step-by-step explanation:

x = nhmber

x² = its square

then:

The sum of a number and its square is 42 is:

x² + x = 42

Marisha walks 8 miles in 5 days. If she walks at the same rate, how far
does Marisha walk in 40 days?

Answers

Answer:

56 miles

Step-by-step explanation:

Let f () = x^2, g(x) = 2x – 1. and h (x)= x-4
Evaluate h(g(-5)).?

Answers

Answer:

-15.

Step-by-step explanation:

G(-5) = 2(-5) - 1

= -10 - 1

= -11

H(-11) = -11 - 4

= -15

Hope this helps!

Answer:

h(g(-5))= -15

Step-by-step explanation:

We are asked to find h(g(-5)).

First, we must find g(-5).

We know that g(x)=2x-1. Therefore, to find g(-5), we must plug -5 in for x.

g(x)= 2x-1

g(-5)= 2(-5) -1

Multiply 2 and -5.

g(-5)= -10 -1

Subtract 1 from -10.

g(-5)= -11

Now, we can substitute -11 in for g(-5).

h(g(-5)

g(-5)= -11

h(-11)

Now, we must find h(-11).

We know that h(x)= x-4. So, we can plug -11 in for x.

h(x)= x-4

h(-11)= -11-4

Subtract 4 from -11.

h(-11)= -15

h(g(-5)=  -15

Factoring Polynomials, please help.

Answers

Answer:

(x²)² + 2(9) + 9²

(x² + 9)²

Step-by-step explanation:

Given expression in the question is,

(x⁴ + 18x²+ 81)

We have to factorize this expression.

We know the formula of (a + b)² = a² + 2ab + b²

Comparing this formula with the given expression,

a = x²

b = 9²

By substituting these values in the given formula,

Therefore, (x⁴ + 18x²+ 81) = (x²)² + 2(9) + 9²

                                         = (x² + 9)²

Coleman uses his graphing calculator to find all of the solutions to the equation shown below.
23 + 3 = -24 + 4
What are ALL of the solutions to the equation, rounded to the nearest hundredth?
A.
x = 0.82 and 3.55
B. O x = -1.38 and 0.37
C.
x = 0.37 and 3.55
D.Ox=-1.38 and 0.82

Answers

Answer:

The correct option is;

D. x = -1.38 and 0.82

Please find attached the combined function chart

Step-by-step explanation:

The given equation is x³ + 3 = -x⁴ + 4

Plotting the equation using Excel, we have;

f(x) = x³ + 3, h(x) = -x⁴ + 4

x                                             f(x)                                       h(x)

-1.4                                         0.256                                   0.1584

-1.39                                       0.314381                              0.26699

-1.38                                       0.371928                             0.373261

-1.37                                       0.428647                             0.477246

-1.36                                       0.484544                             0.57898

Which shows an intersection at the point around -1.38

x                                          f(x)                                     h(x)

0.77                                    3.456533                         3.64847

0.78                                    3.474552                         3.629849

0.79                                    3.493039                          3.610499

0.8                                         3.512                                3.5904

0.81                                      3.531441                           3.569533

0.82                                       3.551368                          3.547878

0.83                                       3.571787                            3.525417

Which shows the intersection point around 0.82

Therefore, the correct option is x = -1.38 and 0.82

From the graphing calculator the intersection point is given as

x = -1.3802775691 and 0.81917251339.

number (√12+√10-√2) is?
a) an irrational number
b) equal to zero
c) positive rational number
d) negative number​

Answers

c...................

A parent rewards a child with 50 cents for each correctly solved mathematics problem and fines the child 30 cents for each incorrectly solved problem. If the child nets $22.00 after 100 problems. How many problems were solved correctly?

Answers

Answer:

65

Step-by-step explanation:

Let c = number of correct answer.

Let i = number of incorrect answers.

There are 100 questions, so

c + i = 100

The correct answers are worth 0.5c.

The incorrect answers are worth -0.3i (a negative value because 30 cents is taken away for each incorrect answer)

The total worth of the answers is 0.5c - 0.3i. The total worth of the answers is $22.00, so the second equation is

0.5c - 0.3i = 22

We have a system of two equations in 2 unknowns:

c + i = 100

0.5c - 0.3i = 22

We'll use the substitution method to solve the system of equations.

Solve the firt equation for c:

c = 100 - i

Now substitute 100 - i for c in the second equation.

0.5(100 - i) - 0.3i = 22

50 - 0.5i - 0.3i = 22

-0.8i = -28

i = 35

c = 100 - i

c = 100 - 35

c = 65

Answer: 65 problems were solved correctly.

area of a triangle two sides of which are 18 cm and 12 cm

and the perimeter is 44 cm.​

Answers

Answer:

≈ 83.9 cm²

Step-by-step explanation:

Given:

P = a+b+c = 44 cma = 18 cmb = 12 cm

Then:

c= P -(a+b) = 44 -(18+12) = 14 cm

Area of  the triangle is found by using Herons formula:

A = √s(s-a)(s-b)(s-c),

where s = P/2 = 44/2 = 22 cm

A = √22(22-18)(22-12)(22-14) = √22*4*10*8= √7040 ≈ 83.9 cm²

Answer:

[tex]\huge \boxed{\mathrm{83.9 \ cm^2}}[/tex]

Step-by-step explanation:

Two sides of the triangle are given.

The perimeter is given.

We need to solve for the third side.

[tex]P=a+b+c[/tex]

[tex]P= \sf perimeter[/tex]

[tex]a,b,c= \sf side \ lengths[/tex]

[tex]44=18+12+c[/tex]

[tex]c=14[/tex]

The measure of the third side is 14 cm.

When three sides of the triangle are given, we can solve for the area using Heron’s formula.

[tex]A=\sqrt{s(s-a)(s-b)(s-c)}[/tex]

[tex]s=\sf semi \ perimeter[/tex]

[tex]\displaystyle s=\frac{P}{2} =\frac{44}{2} =22[/tex]

Plugging in the values and evaluating.

[tex]A=\sqrt{22(22-18)(22-12)(22-14)}[/tex]

[tex]A = 83.904708...[/tex]

The area of the triangle is approximately 83.9 cm².

40 ➗ [24 - 4 x (2 + 3) ]

What is the value of this expression?

Answers

Answer: this is your answer

  10

_____

6-5x

Answer:

1.7-20x OR 10/6-5x

Step-by-step explanation:

40÷(24-4x(2+3))

first you add the last set of ()

40÷(24-4x(5))

then you multiply by 4x

40÷(24-20x)

since you can't subtract those two you do this

40÷24-20x

divide 40 and 24

you get 1.66666667 then you round up

1.7-20x

                  OR

you put 40/24-20x

divide the top and the bottom by 4

(40÷4)/(24÷4) -(20x÷4)

and your answer will be

10/6-5x

how do you break down 213 in times

Answers

Answer:2 hundred+1 tens+3 ones

Step-by-step explanation:

Homer Simpson entered a pie eating contest at the county fair. Homer was determined to win and went into training for 6 days. Each
day, he ate 4 more pies than the day before. Homer ate 150 pies while in training. How many pies did he eat each day?
Day 1: type your answer...
Day 2: type your answer....
Day 4: type your answer....
Day 3: type your answer....
type your answer...
Day 5: type your answer...
Day 6: type your answer...


Answers

Answer:

151923273135

Step-by-step explanation:

He ate 15, 19, 23, 27, 31, 35 pies for each day.

What is addition?

Addition in math is a process of combining two or more numbers.

Given that, Homer Simpson entered a pie eating contest at the county fair. Homer was determined to win and went into training for 6 days, each day, he ate 4 more pies than the day before. Homer ate 150 pies while in training.

Let he ate x pie for 1st day, then according to question,

1st day = x

2nd day = x+4

3rd day = x+8

4th day = x+12

5th day = x+16

6th day = x+20

He ate 150 pies for 6 days

Therefore, x+x+4+x+8+x+12+x+16+x+20 = 6x + 60 = 150

6x = 90

x = 15

Hence, he ate 15, 19, 23, 27, 31, 35 pies for each consecutive day.

For more references on addition, click;

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Quick please -4 (-2x - 4)

Answers

Answer:

-10x

Step-by-step explanation:

-2x-4=-6x

-4-6x = -10x

Answer:

x = -2

Step-by-step explanation:

To solve for x:

Equation: -4(-2x - 4) = -8x - -16-8x - -16 = -8x + 16Divide each side by -8 so it now looks like this: x = -2

Therefore, x equals -2.

To simplify the equation:

-2x - 4 = -6x-4(-6x) = 24x

you are building a new house and need to pour 1200 cubic feet of concrete for the foundation. the concrete truck delivers concrete by the cubic yard. how much concrete do you need to buy from the concrete company?

Answers

Answer:

400 cubic yards

Step-by-step explanation:

There are three cubic feet in each cubic yard

Which choice shows the product of 22 and 39?
(22)(39) = 858
22 x 39 = 748
22 + 39 = 61
22. 39 = 648

Answers

Answer: (22)(39) = 858.

Step-by-step explanation:

Product of a number simply means that one has to multiply the numbers that are given. For example, if a student is told to find the product of 2 and 5, it simply means that 2 × 5 = 10.

Regarding the above question, the product of 22 and 39 is represented by: (22)(39) = 858. It should be noted that 22 × 39 = 858

how do you find the area of a circle and what is the formula for it

Answers

Answer:

Read Exp:

Step-by-step explanation:

Area = 3.14 x r^2

I've Included a picture to tell you how to get the diameter as well as the circumference.

Answer:

formula is πr² ( pi x radius squared)

Step-by-step explanation:

the value of π is 3.142...

multiply this value with the squared radius of the circle and you'll get your answer.

For example:

we have a circle with diameter 5

so,  π x 5² = 3.142 x 25 = 78.5

In a photograph, Alison stands next to her brother Caleb. Alison is 4 cm tall in the photograph. Her actual height is 60 in. Caleb is 3.2 cm tall in the photograph.
What is his actual height?
(Show your work)

Answers

Answer:

Caleb's actual height is 48 inches

Step-by-step explanation:

Alison's height in the photograph= 4 cm

Caleb's height in the photograph= 3.2 cm

Alison's actual height= 60 in

Caleb's actual height=x in

60 in= 152.4 cm

Alison's height in photograph : Her actual height = Caleb's height in photograph : his actual height

4cm : 152.4cm = 3.2cm : xcm

4 / 152.4 = 3.2 / x

Cross product

4 * x = 152.4 * 3.2

4x = 487.68

Divide both sides by 4

x= 121.92 cm

121.92 cm = 48 in

Caleb's actual height is 48 in

Which of the following represents a constant from the expression given? 15x^2 + 2x + 9

A. 9
B. 15
C. 2
D. 24

Answers

Answer:

A) 9

Step-by-step explanation:

Hello!

A constant is a fixed and defined number.

A constant is any number that does not have a variable next to it

The only number in the equation that follows this is 9

Hope this Helps!

The constant from the expression is 9. option A

What are algebraic expressions?

Algebraic expressions are defined as expressions that are made up of variables, constants, factors and coefficients.

Also, these algebraic expressions are made up of arithmetic operations, such as;

AdditionMultiplicationDivisionBracketParenthesesSubtraction

From the information, we have that the expression is given as;

[tex]15x^2 + 2x + 9[/tex]

We have then that;

The terms are; 15x , 2x and 9

The coefficient of x is 2

The coefficient of x² is 15

The constant is 9

Learn about algebraic expressions at: https://brainly.com/question/4344214

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When the solution of x2 + 9x - 9 is expressed as
9&
2
what is the value of r?
X
-btvb2 - 4ac
2a
117
O 54
045
09

Answers

answer

r = b²-4ac

= 81 + 36

= 117

The calorie count of a serving of food can be computed based on its composition of​ carbohydrate, fat, and protein. The calorie count C for a serving of food can be computed using the formula C = 6h + 11f + 7p, where h is the number of grams of carbohydrate contained in the​ serving, f is the number of grams of fat contained in the​ serving, and p is the number of grams of protein contained in the serving. Solve this formula for​ f, the number of grams of fat contained in a serving of food.

Answers

Answer:

see below (I hope this helps!)

Step-by-step explanation:

C = 6h + 11f + 7p

Get all non-f terms on one side:

C - 6h - 7p = 11f

Divide by 11:

f = [tex]\frac{C - 6h - 7p}{11}[/tex]

Only two four and eight​

Answers

Answer:

2. -6

4. 0

8. 2

Step-by-step explanation:

Order of Operations: BPEMDAS

2

Step 1: Write out expression

-(8 - 2)

Step 2: Parenthesis (Subtract)

-(6)

Step 3: Multiply

-6

4

Step 1: Write out expression

-(0 + 0)

Step 2: Parenthesis (Add)

-(0)

Step 3: Multiply

0

8

Step 1: Write out expression

3 - [-(-1)]

Step 2: Brackets (Multiply)

3 - 1

Step 3: Subtract

2

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