Please help ASAP!!!

Chuck Stone is standing atop a high platform. He fires a rock up into the air with his slingshot. While it is in flight, the rock's distance in feet above the ground f(x) is a quadratic equation of time in seconds (x). This situation is modeled by the following function: f(x) = -5x^2 + 40x + 30.

a. How high above the ground is the platform?
30
b. How long does it take for the rock to hit the ground? Show all work to receive full credit!

is 30 correct for a? and please help me with b! Thank you!!!

Answers

Answer 1

Answer:

a) the platform is 110 feet above the ground.

b)  It takes 8.69 sec for the rock to hit the ground

Step-by-step explanation:

This situation is modelled by the following function: [tex]f(x) = -5x^2 + 40x + 30\\[/tex]

We need to answer the following questions.

a) How high above the ground is the platform?

First we find x using the formula: [tex]x=-\frac{b}{2a}[/tex]

we have b = 40 and a = -5

Putting values and finding x

[tex]x=-\frac{b}{2a}\\x=-\frac{40}{2(-5)}\\x=-\frac{40}{-10}\\x=4[/tex]

Now putting x=4 in the function to find how high above the ground is the platform

[tex]f(x) = -5x^2 + 40x + 30\\Put\:x=4\\f(4)=-5(4)^2+40(4)+30\\f(4)=-5(16)+160+30\\f(4)=-80+160+30\\f(4)=110[/tex]

So, the platform is 110 feet above the ground.

b) How long does it take for the rock to hit the ground? Show all work to receive full credit!

We will factorise the given function [tex]f(x) = -5x^2 + 40x + 30[/tex] to find the time taken to hit the ground.

We can solve the equation using quadratic formula: [tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]

We have a =-5, b=40, c=30

Putting values and finding x

[tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}\\x=\frac{-40\pm\sqrt{(40)^2-4(-5)(30)}}{2(-5)}\\x=\frac{-40\pm\sqrt{1600+600}}{-10}\\x=\frac{-40\pm\sqrt{2200}}{-10}\\x=\frac{-40\pm46.9}{-10}\\x=\frac{-40+46.9}{-10},x=\frac{-40-46.9}{-10} \\x=-0.69,x=8.69[/tex]

So, we get values of x: x = -0.69 and x=8.69

As time cannot be negative, so we take x=8.69

So, It takes 8.69 sec for the rock to hit the ground


Related Questions

Find the angle of elevation
from point C to point A.
A
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59°
402 m
C
B
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180-90-59 = 31 degrees

the clock below shows what time mason mom drop him off for practice. what time does his mom drop him off

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Answer:

4:05?

Step-by-step explanation:

Answer:

?

Step-by-step explanation:

This doesn't make sense.

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Answer:

a=18units

x=99°

y=108°

Step-by-step explanation:

Perimeter=sum of lengths around the kite.

Given that two sides each are congruent:

P=12+12+a+a

60=24+2a

60-24=2a

36=2a

a=36/2=18

x=99°

y+99+99+54=360°(sum of interior angles of a quadrilateral)

y+252=360

y=360-252

y=108°

Simplify the expression by combining like terms.
15 + 12z– 5z + 4y- 7

Answers

Answer: = 4y + 7z + 8

Answer:

7z+4y+8

Step-by-step explanation:

Collect the like terms so 12z-5z would be 7z, then since there is only 1 y term it would be 4y, and -7 + 15= 8

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Answers

Answer:

160

Step-by-step explanation:

there are 3 rectangles in the irregular figure cut across them with your pen by drawing lines and indicate using dimensions.

1. 4 by 6 =24

2. 6 by 11 =66

3. 7 by 10= 70

add them altogether

=160

Write y=−4x−4 in standard form .

Answers

Answer:

Y=-4x-4= [tex]x=- \frac{y+4}{4}[/tex]

Step-by-step explanation:

Answer: The answer is x=–y+4/4?

Step-by-step explanation:

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Answer:

4 3/4 inches

Step-by-step explanation:

Answer:

[tex]4\frac{3}{4}[/tex]

Step-by-step explanation:

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Answers

Answer:

Midpoint Formula= (x1+x2)/2, (y1+y2)/2

Plug in the numbers

Answer= (0, 0)

I hope this helps you!!

What is [tex]\frac{2}{5}[/tex] as a decimal

Answers

Answer:

0.4

Step-by-step explanation:

2 x 20=40

5 x 20=100

40/100= 0.40 simplified as 0.4

Answer:

2/5 as a decimal is 0.4

Step-by-step explanation:

2 divided by 5 would equal 0.4

please help first answer will be marked brainiest

Answers

Answer:

6x

Step-by-step explanation:

add sides up

Hey, Whats The answer please explain your answer marking brainliest:D...............................

Answers

Answer:

B. Kevin is correct. Amy did not line up the decimals correctly.

Step-by-step explanation:

Answer: B

Step-by-step explanation:

    B- kevin is correct because amy did not line up the decimals correctly

Need help for this one!!

Answers

SAS hopefully this helps!

Which of the following is equivalent to 7(a + 4) + 15?

7a + 43
7a + 19
7a + 60
28a + 15

Answers

Answer:

7a + 43

Step-by-step explanation:

Let's simplify step-by-step.

7(a+4)+15

Distribute:

=(7)(a)+(7)(4)+15

=7a+28+15

Combine Like Terms:

=7a+28+15

=(7a)+(28+15)

=7a+43

Answer:

7a + 43

Step-by-step explanation:

Given:

7(a + 4) + 15

Solve:

Distribute:

7(a + 4) + 15

7 × a = 7a7 × 4 = 28

Now we have:

7a + 28 + 15

Add the numbers:

28 + 15 = 43

7a + 43

Therefore, 7a + 43 is equivalent to 7(a + 4) + 15.

Kavinsky.

**NEED THIS WITHIN 5 MINS** Stan’s employer pays for 45% of his annual health insurance premium of $4,567.00. Stan pays the remaining balance by having it deducted in equal amounts from his 26 paychecks throughout the calendar year. How much will Stan have deducted from each paycheck?

Answers

Answer:

$88.3

Step-by-step explanation:

Here 42% of annual health premium($5450)=*5450

                                                                     =$2289

This amount is being paid by the company means it is deducted amount in one year.

One year has 26 paychecks so above amount divided by 26 is rebate amount in each paycheck.

Deducted amount=

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Solve Each Equation PLS SHOW WORK

|5k-8| / 10 = 2

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Answers

Answer:

The maximum value of k = 5 ³/₅ and the minimum value of k = -2 ²/₅

Step-by-step explanation:

Given;

[tex]\frac{|5k-8|}{10} = 2\\\\|5k-8| = 20[/tex]

Simplifying further;

5k - 8 = 20 ------- (1)

5k - 8 = -20------(2)

Solving equation (1)

5k - 8 = 20

5k = 28

k = 28 /5 = 5 ³/₅

Solving equation (2)

5k - 8 = -20

5k = -20 + 8

5k = -12

k = -12 / 5  = -2 ²/₅

Thus, the maximum value of k = 5 ³/₅ and the minimum value of k = -2 ²/₅

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Answers

Answer:

i believe >

Step-by-step explanation:

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Answers

Answer:

(0, 0)

Step-by-step explanation:

None

I’m alive but I’m dead. Sad :(

Jamal makes $186 a week at his job. He plans to save 5% of his paycheck for a P.Y.F account. How much money will Jamal put in his P.Y.F account this week.

Answers

Answer:

$9.30

Step-by-step explanation:

Answer:

Jamal will put $9.30 in his P.Y.F. account this week.

Step-by-step explanation:

Jamal makes $186 a week. He plans to save 5% of that in his P.Y.F. account.

%5 of $186 is $9.30 ($186/20).

This week, he will put $9.30 in his P.Y.F. account.

Hope this helps!

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Answers

Answer:

-2u(3+2) + t(7+5)

Tip: arranging the like terms next to each other helps to keep things from getting messy.

Can you please help me with 6

Answers

Answer:

Third choice, 3/4

Step-by-step explanation:

Add all the cubes together, 12 + 5 + 3 = 20

There's a 12/20, which is 3/5, chance you'll get a green cube

5/20, which is 1/4, chance you'll get a blue cube

And there's a 3/20 chance you'll get a yellow cube

The probability of not getting a blue cube is 12/20 + 3/20 = 15/20 = 3/4

Solve the system of equations using the substitution method.

y=2+56x
4x−3y=3

Enter your answer in the boxes.

(___,___)

Answers

Answer:

(6,7)

Step-by-step explanation:

took the test, was correct.

x= 6, y=7

solve for the first variable in one of the equations, then substitute the result into the other equations.

The value of x is 0.05 and y is 4.8 for given system of equations.

What is Equation?

Two or more expressions with an Equal sign is called as Equation.

The given  system of equations are

y=2+56x...(1)

4x−3y=3...(2)

Substitute (1) in equation (2)

4x-3(2+56x)=3

4x-6+168x=3

172x-6=3

Add 6 on both sides

172x=9

Divide both sides by 172

x=9/172

x=0.05

Now plug in x value in equation 1

y=2+56(0.05)

=2+2.8

y=4.8

Hence, the value of x is 0.05 and y is 4.8 for given system of equations.

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13x + 9 equals 6x - 12​

Answers

Answer: okay is that a question?

Step-by-step explanation:

Answer:

[tex]given \\ 13x + 9 = 6x - 12 \\ = > 13x - 6x = - 12 - 9 \\ = > 7x = - 21 \\ = > x = \frac{ - 21}{7} \\ = > x = - 3[/tex]

it may be helpful for youif any problem then consulting with me

Identify the slope shown in the linear equation below. y = - 5x + 3

Answers

Answer:

Slope: -5 Y-intercept: 3

Step-by-step explanation:

the slope intercept of a linear equation is:

y=mx+b

were m is slope. and b is the y intercept

therfore the problem is:

y=-5x+3

m=-5 so the slope is -5

b=3 so the y-intrercept is 3

Answer:

-5

Step-by-step explanation:

The slope is always in front of the x

A pair of dice is tossed. what is the probability of getting sum of 5 or 9?
A)7/9
B)5/9
C)1/9
D)2/9​

Answers

Answer:

[tex]Probability = \frac{2}{9}[/tex]

Step-by-step explanation:

Given:

A pair of dice

Required

Determine the probability of a sum of 5 or 9

Let the sample space of the first die be S1 and the second, S2

[tex]S_1 = {1,2,3,4,5,6}[/tex] --- 6 outcomes

[tex]S_2 = {1,2,3,4,5,6}[/tex]  --- 6 outcomes

Number of sample space, n is:

[tex]n = 6 * 6[/tex]

[tex]n = 36[/tex]

Next, we list out all possibilities of obtaining a sum of 5

[tex]Sum\ of\ 5 = \{(1,4),(2,3),(3,2),(4,1)\}[/tex]

n(Sum5 )= 4

Next, we list out all possibilities of obtaining a sum of 9

[tex]Sum\ of\ 9 = \{(3,6),(4,5),(5,4),(6,3)\}[/tex]

n(Sum9)= 4

The required probability is then calculated as:

[tex]Probability = \frac{n(Sum9)}{Total} + \frac{n(Sum5)}{Total}[/tex]

[tex]Probability = \frac{4}{36} + \frac{4}{36}[/tex]

Take LCM

[tex]Probability = \frac{4+4}{36}[/tex]

[tex]Probability = \frac{8}{36}[/tex]

Simplify

[tex]Probability = \frac{2}{9}[/tex]

3. State what additional information is required in order to know that the triangles are congruent by the SSS Triangle Congruence Postulate

Answers

The additional information required in order to know that the triangles are congruent by the SSS Triangle Congruence Postulate is that Line ML is equivalent to line YL. Option A

What is the SSS congruence postulate?

The SSS congruence theorem states that  If all the sides of one triangle are equivalent to the corresponding three sides of the second triangle, then,  the two triangles are said to be congruent.

From the diagram given, we have;

Triangles NLMTriangle LNY

For the three sides of triangles NLM to be equivalent to that of LNY;

Line MN must be equal to line YL

Thus, the additional information required in order to know that the triangles are congruent by the SSS Triangle Congruence Postulate is that Line ML is equivalent to line YL. Option A

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Help pls! 10 points!

Answers

Do I have to do all of them?

another trigonometry question

i just want this test to be over >-

Answers

Answer:

e) cos(90-x)

Step-by-step explanation:

sinx=cos(90-x)

what is the slope of the line described by the equation below y-6=-2(x-8)

Answers

Answer:

-2

Step-by-step explanation:

you have to rearange in the form of

y=mx+b, where m is the slope

y -6= -2( x-8)

y = 6 -2x + 16

y= -2x +22

slope is -2

I have 17 warnings how am I not banned from the app yet?

Answers

You should ask a moderator

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Answers

Answer:

2^6

Step-by-step explanation:

2^6=64

2x2x2x2x2x2=64

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