10
Driving. In an emergency, the distance,
d m, it takes for a car moving at a
speed of v m/s to stop completely is
given by d = 0.15v2 + v.
(i) When the car has only 80 m to stop,
show that 3v2 + 20v – 1600 < 0.
(ii) Solve the inequality in part (i) to
find the maximum speed of the car.​

Answers

Answer 1

Answer:

i) The proof is below

ii) The maximum speed is 20m/s

Explanation:

(i) When the car has only 80 m to stop, show that [tex]3v^2+20v-1600<0.[/tex]

The distance, [tex]d[/tex] [tex]m[/tex], it takes for a car moving at a speed of [tex]v[/tex] [tex]m/s[/tex]  to stop completely is given by [tex]d=0.15v^2+v[/tex]

The car must stop before the 80 m, so the distance to stop is less than 80 m:

                       [tex]d<80[/tex]

Substitute:

                      [tex]0.15v^2+v<80[/tex]

Multiply both sides by 20:

             [tex]20\times 0.15v^2+20\times v<20\times 80\\\\3v^2+20v<1600[/tex]

Subtract 1600 from both sides:

            [tex]3v^2+20v-1600<0[/tex]

Which is the expression you wanted to prove.

(ii) Solve the inequality in part (i) to find the maximum speed of the car.​

To solve the inequality you need to factor the left side:

Put 20v as 80v - 60v

         [tex]3v^2+80v-60v-1600<0[/tex]

Use commutative property of addition

         [tex]3v^2-60v+80v-1600<0[/tex]

Use associative property

         [tex](3v^2-60v)+(80v-1600)<0[/tex]

Factor each binomial:

        [tex]3v(v-20)+80(v-20)<0[/tex]

Common factor [tex](v-20)[/tex]

          [tex](v-20)(3v+80)<0[/tex]

There are two possible solutions: 1) the first factor is positive and the second negative, and 2) the first factor is negative and the second positive.

         

1. First tentative solution

              [tex]v-20>0\\\\v>20\\\\3v+80<0\\\\3v<-80\\\\ v<-80/3\\\\v<-26.26[/tex]

The speed cannot be greater than 20m/s and less than - 26.26 m/s at the same tine, thus, there are not solutions for this assumption.

2. Second tentative solution

              [tex]v-20<0\\\\v<20\\\\3v+80>0\\\\3v>-80\\\\ v>-80/3\\\\v>-26.26[/tex]

You are looking for an upper bound, thus the solution is that the speed is less than 20m/s.


Related Questions

Question 3 of 50
Line A in the given graph has what kind of slope?
-1/2
0
undefined

Answers

tbh idrk sry bye bye mush

Solve the following quadratic inequality 2x^2+3x-5>0

Answers

Answer:

x < -2.5 and x > 1

Step-by-step explanation:

The answer is 7x
If is wrong tell me then

Table 1.19 Frequency of Number of Movies Viewed
1. Using the tables, find the percent of data that is at most two. Which table did you use and why?
2. Using the tables, find the percent of data that is at most three. Which table did you use and why?
3. Using the tables, find the percent of data that is more than two. Which table did you use and why?
4. Using the tables, find the percent of data that is more than three.

Answers

Final answer:

To find the percent of data that is at most two or three, locate the corresponding column in the frequency table and divide the frequency by the total number of data points. To find the percent of data that is more than two, subtract the percent at most two from 100.

Explanation:

1. To find the percent of data that is at most two, I would look at the table that displays the frequency of the number of movies viewed. I would locate the column that represents 'at most two' and find the corresponding frequency. To calculate the percent, I would divide this frequency by the total number of data points and multiply by 100.

2. To find the percent of data that is at most three, I would use the same procedure as in the previous question, but this time I would find the column representing 'at most three.'

3. To find the percent of data that is more than two, I would subtract the percent of data that is at most two from 100. This is because the percent of data that is at most two includes any data that is less than or equal to two.

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select the correct answer.
which expression gives the same result as​

Answers

Answer:

b

Step-by-step explanation:

a triangle is reduced. What is the perimeter of the reduced triangle, in inches.

Answers

Answer:

the perimeter is 36

Step-by-step explanation:

Answer:

The correct answer is 36

Step-by-step explanation:

Edg. 2020

It is 9:00. What is the measure of the smaller angle between the hour hand
and minute hand after three minutes? *

Answers

Answer:

The hour hand is three-fourths of the way from the "4" to the "5; that is, ... What is the angle between the hour hand and the minute hand at 4:40? ... What is the measure of the smaller angle formed by the hands of an analog watch if the hour hand is on the ... One has to account, however, for the 10 minutes that have passed.Step-by-step explanation:

write 3.005 using words

first person is the brainliest

Answers

Answer:

three and five hundreths

Answer:

three and five thousandths

Step-by-step explanation:

3 counts as one and the decimal is said as "and" and the spaces after the decimal are tenths,hundredths and thousandths

Subtract. (5 x 2 −3x−2)−(−2 x 2 −x+10)

Answers

(5[tex]x^2[/tex] − 3x −2) − (−2[tex]x^2[/tex] − x + 10) = = 7[tex]x^2[/tex]  - 2x - 12

Step-by-step explanation:

We have,

(5[tex]x^2[/tex] − 3x − 2) − (− 2[tex]x^2[/tex] − x + 10)

To subtract (5[tex]x^2[/tex] − 3x − 2) − (− 2[tex]x^2[/tex] − x + 10) = ?

(5[tex]x^2[/tex] − 3x −2) − (−2[tex]x^2[/tex] − x + 10)

= 5[tex]x^2[/tex] − 3x − 2 + 2[tex]x^2[/tex] + x - 10

= (5[tex]x^2[/tex] + 2[tex]x^2[/tex]) + ( − 3x + x) + (- 2 - 10)

= 7[tex]x^2[/tex] + ( -2x) + ( - 12)

= 7[tex]x^2[/tex]  - 2x - 12

∴ (5[tex]x^2[/tex] − 3x −2) − (−2[tex]x^2[/tex] − x + 10) = = 7[tex]x^2[/tex]  - 2x - 12

d = 23 in.
Find the circumference of the circle

Answers

Answer:

72.22in

Step-by-step explanation:

c=d*pie

23*3.14

Answer:

About 72 in.

Step-by-step explanation:

The circumference = π x the diameter of the circle (Pi multiplied by the diameter of the circle).

c = π·23

c= 72.2566310326

I hope this helps!

brainliest is appreciated... :}

Consider the dice A, B, and C below. The opposite sides have the same values as those shown.
A(2,9,4) B(1,8,6) C(3,7,5)
a) If A is rolled against B with the higher number the winner, which should you bet on? Why?
Explain in terms of probability.
b) What if B is rolled against C?
c) Now what about C against A?

Answers

Answer:

a) A

b) B

c) C

Step-by-step explanation:

There are 9 different outcomes when 2 die are rolled.

a) A & B : A has a higher chance of winning, i.e probability of 5/9

(A,B) : (2,1) (9,1) (9,8) (9,6) (4,1)

In other 4 possible outcomes, B will win which is a probability of 4/9 (less than 5/9)

b) B & C: B has a higher chance of winning, i.e probability of 5/9

(B,C) : (8,3) (8,7) (8,5) (6,3) (6,5)

In other 4 possible outcomes, C will win which is a probability of 4/9 (less than 5/9)

c) A & C: C has a higher chance of winning, i.e probability of 5/9

(A,C) : (2,3) (2,7) (2,5) (4,7) (4,5)

In other possible outcomes, A will win which is a probability of 4/9 (less than 5/9)

For a project in statistics class, a pair of students decided to invest in two companies, one that produces software and one that does biotechnology research. Dean purchased 14 shares in the software company and 14 shares in the biotech firm, which cost a total of $812. At the same time, Carrie invested a total of $5,767 in 100 shares in the software company and 99 shares in the biotech firm. How much did each share cost?

Answers

Final answer:

Each share in the software company costs approximately $5,195.14 and each share in the biotech firm costs approximately $5,137.15.

Explanation:

To find out how much each share costs, we need to solve a system of equations. Let's call the cost of each share in the software company 'x' and the cost of each share in the biotech firm 'y'.

From the given information, we know that Dean purchased 14 shares in each company for a total cost of $812. This gives us the equation 14x + 14y = 812.

Similarly, Carrie invested a total of $5,767 in 100 shares in the software company and 99 shares in the biotech firm. This gives us the equation 100x + 99y = 5,767.

Now, we can solve this system of equations using either substitution or elimination method.

Using the elimination method, multiply the first equation by 99 and the second equation by 14 to make the coefficients of 'x' in both equations equal:

1386x + 1386y = 79861400x + 1386y = 80718

Now subtract the first equation from the second equation:

(1400x + 1386y) - (1386x + 1386y) = 80718 - 798614x = 72732

Divide by 14 on both sides to find the value of 'x':

x = 72732 / 14x = 5195.14

Now substitute the value of 'x' back into one of the original equations to find the value of 'y'. Using the first equation:

14(5195.14) + 14y = 81272732.08 + 14y = 81214y = -71920.08y = -71920.08 / 14y = -5137.15

Therefore, each share in the software company costs approximately $5,195.14 and each share in the biotech firm costs approximately $5,137.15.

What is the y-value when x equals -16?
y = -200 - 12(x)

Answers

Answer:

Step-by-step explanation:

y = -200 - 12(x)

x = -16

y = -200 - 12(-16)

y = -200 + 192

y = -8

Answer:

y=-8

Step-by-step explanation:

y=-200-12(-16)

y=-200+192

y=-8

What is the solution set of the given equation?


4y - 6y + 9y = -2


{-2/11}

{2/7}

{2/11}

{-2/7}

Answers

The solution set it {-2/7}

Rosa is participating in a fun run to raise money for the West Side Children's Hospital. The run is held at Rosa's high school track. The more laps Rosa runs around the track, the more money she raises for the hospital.
There is a proportional relationship between the number of laps Rosa runs, x, and the amount of money she raises for the hospital (in dollars), y.
x (laps) y (dollars)
1 $5
2 $10
3 $15
4 $20
Write an equation for the relationship between x and y.
y=

Answers

Final answer:

The equation representing the proportional relationship between the number of laps Rosa runs and the amount of money she raises is y = 5x. This linear equation suggests that for every lap completed, $5 is earned for the hospital.

Explanation:

The relationship between the number of laps Rosa runs (x) and the amount of money she raises for the hospital (y) can be described by a linear equation because there is a proportional relationship between x and y. We can see from the values given that each lap corresponds to $5. Therefore, the slope (change in y divided by the change in x) is $rac{$5}{1 lap} = $5$ per lap. Since there is no initial fee mentioned (y-intercept, b), the equation is simply the slope times the number of laps.

So, we can write the equation as y = 5x. This equation tells us that for every lap Rosa runs, she will raise $5. If we plot this relationship on a graph with x as the independent variable and y as the dependent variable, we would get a straight line that passes through the origin (0,0).

Slove for x? X+16=4x-5

Answers

Answer:

x=7

Step-by-step explanation:

x+16=4x-5

16=4x-x-5

16=3x-5

3x=16+5

3x=21

x=21/3

x=7

Answer:

x=7

Step-by-step explanation:

Write an inequality that represents 54 less than 1/2 of a number is more than 233

Answers

[tex]\frac{1}{2}[/tex]x - 54 > 233 would be your inequality.

⭐ Answered by Hyperrspace (Ace) ⭐

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The inequality that represents 54 less than 1/2 of a number is more than 233 would be; 1/2 x - 54 > 233

What is a solution set to an inequality or an equation?

If the equation or inequality contains variable terms, then there might be some values of those variables for which that equation or inequality might be true. Such values are called solution to that equation or inequality. Set of such values is called solution set to the considered equation or inequality.

Given that 54 less than 1/2 of a number is more than 233

Let the number be x.

So, 1/2 of a number means 1/2x

54 less than 1/2 of a number = 1/2 x - 54

Therefore,

Hence, 1/2 x - 54 > 233 would be your inequality.

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Mr. Benton is contemplating which chauffeured car service to take to the airport. The first costs $7 up front and $2 per kilometer. The second costs $19 plus $1 per kilometer. For a certain driving distance, the two companies charge the same total fare. What is the distance? What is the total fare?

Answers

Answer:

12 kilometers

$31 total fare

Step-by-step explanation:

7 + 2x   company A

19 + x .   Company B

set these equal and solve for x

x is number of kilometers

7 + 2x = 19 + x

2x = 12 + x

x = 12 kilometers

7 x 2 (12) = $31

A jet leaves the Charlotte, North Carolina, airport traveling at an average rate of 564 km/h. Another jet leaves the airport one-half hour later traveling at 744 km/h in the same direction. Use an equation to find how long the second jet will take to overtake the first.


A.
1 17/30 h


B.
2 1/15 h


C.
− 1 17/30 h

Answers

Answer:

[tex]A.\ 1\frac{17}{30}\ hours[/tex]

Step-by-step explanation:

[tex]Let\ second\ jet\ overtake\ first\ in\ x\ hours.\\\\[/tex]

Distance covered by first jet:

[tex]Speed\ of\ first\ jet=564\ km/h\\\\Time=x+\frac{1}{2}\\\\Distance\ covered=speed\times time\\\\Distance\ covered=564\times (x+\frac{1}{2})=564x+564\times \frac{1}{2}\\\\Distance\ covered=564x+282[/tex]

Distance covered by second jet:

[tex]Speed\ of\ second\ jet=744\ km/h\\\\Time=x\\\\Distance\ covered=speed\times time\\\\Distance\ covered=744\times x\\\\Distance\ covered=744x[/tex]

[tex]Distance\ covered\ by\ both\ the\ jet\ in\ x\ hours\ is\ equal.\\\\744x=564x+282\\\\744x-564x=282\\\\180x=282\\\\x=\frac{282}{180}=\frac{6\times 47}{6\times 30}\\\\x=\frac{47}{30}\ hours\\\\x=1\frac{17}{30}\ hours[/tex]

If V6x - 9 = x, what is the value of x ?​

Answers

Answer:

9/5

Step-by-step explanation:

Given that ,

⇒ 6x - 9 = x

⇒ 6x - x = 9

⇒ 5x = 9

x = 9/5

Final answer:

To solve the equation V(6x - 9) = x, we square both sides, rearrange the resulting quadratic equation, and factor it to find that x = 3 is the solution.

Explanation:

The equation given is V(6x - 9) = x. To find the value of x, we must solve the equation that involves a square root. First, we need to square both sides of the equation to eliminate the square root:

(V(6x - 9))² = x²
This simplification results in:6x - 9 = x²
Rearrange the equation to bring all terms to one side, effectively setting it to zero:x² - 6x + 9 = 0This is a quadratic equation, and it factors nicely as:(x - 3)² = 0
Therefore, the solution to the equation is x = 3. We can check this by substituting x back into the original equation:V(6(3) - 9) = 3
V(18 - 9) = 3
V9 = 3
3 = 3
Since both sides of the equation are equal, x = 3 is indeed the correct solution.

What is the next term in the following sequence? -3, 4, 11, 18, ...

Answers

Answer:25

Step-by-step explanation: Add 7 to the next term to get the next term.

-3+7=4

4+7=11

11+7=18

18+7=25

Eight more than seven times a number is 8

Answers

Answer:

The number is 0

Step-by-step explanation:

We form an equation using the statement:

8 = 7x + 8

Then we solve it:

8 = 7x + 8

8 - 8 = 7x

0 = 7x

0 ÷ 7 = x

x = 0

A 6-kilogram bag of rice costs $3.80. What is the unit price, rounded to the nearest cent?

Answers

Answer:

The unit price is 63 cent per kilogram bag of rice.

Step-by-step explanation:

Given:

A 6-kilogram bag of rice costs $3.80.

Now, to find the unit price.

So, to get the unit price we use unitary method:

If cost of 6 kilogram bag of rice = $3.80.

Then cost of 1 kilogram bag of rice = [tex]\frac{3.80}{6}[/tex]  = [tex]\$0.633.[/tex]

Thus, the unit price is $0.633 per kilogram bag of rice.

Now, according to question we convert the unit price into cent by using conversion factor:

$1 = 100 cent

$0.633 = [tex]0.633\times 100=63.3\ cent.[/tex]

So, rounded to nearest cent  = 63 cent.

Therefore, the unit price is 63 cent per kilogram bag of rice.

PLEASE HELP FAST!! VERY IMPORTANT!!

Answers

Answer: B, C, D

Step-by-step explanation:

A linear function is a straight line and is written as y=mx+b

A y = 10x is linear

B y = -5x-15 is linear

C y = 2x^2+10 is not linear (the x^2 makes it a parabola)

D y = 12x + 1 is a straight line

E y = -20 is straight line through -20 on the y-axis

F y = 7x^2 + 4 is not a straight line

Which is the slope of the line that passes through the points (−2,4) and (5,−1)?​

Answers

Answer:

-1-4=-5

5+2=7

slope=-5/7

Answer:

slope = -5/7

Step-by-step explanation:

please I need your help​

Answers

Do 5*12 because that's 5*(4+4+4) which the 4s are the base lengths added together. So you have 60 for one part of the figure.

Next, you have 2*4 left to add on to the figure which is 8.

So 60+8=68 is your answer

68 units^2

Hope this helped!

Answer:

The area of the figure is 68ft^2

Step-by-step explanation:

To get the area look for the separate shapes in the figure, there are 2

One has the side lengths of 5ft and 12ft, to get the 12ft length see that one side is segmented into 3 4ft long lines.

5ft * 12ft= 60ft^2

The other shape has the side lengths of 2ft and 4ft

2ft*4ft= 8ft^2

60ft^2 + 8ft^2= 68ft^2

URGENT 15 POINTS
Which event has a probability of 1/2? Select two answers.

A.Rolling a number greater than 6 on a six-sided number cube
B.A flipped coin landing on tails
C.A flipped coin landing on heads or tails
D.Picking a blue marble from a bag of 6 red marbles and 4 blue marbles
E.Rolling an odd number on a six-sided number cube

Answers

Answer:

C and e

Step-by-step explanation:

there are two sides and its pretty much completely random on which side it lands on 2 sides = 1/2 probrability for each side and for the dice there are 3 odd numbers and 3 even numbers so thats half and half of the dice therefore 1/2 probrability

It is C and E. It can't be A or D or B.

The height h in feet of a ball thrown vertically upward from the top of a 288-foot tall building is given by h=288+48t-16t^2 where t is in seconds. How long will it take to he penny to strike the ground.

Answers

6 sec can take penny to strike the ground.

Solution:

Given data:

[tex]H_0=288[/tex] feet

[tex]V_0=48[/tex] feet

[tex]h(t)=288+48t-16t^2[/tex]

Re-arrange the terms from greatest degree to smallest degree.

[tex]h(t)=-16t^2+48t+288[/tex]

We can solve it by applying quadratic formula,

[tex]$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}[/tex]

Here a = –16, b = 48, c = 288

[tex]$t=\frac{-48\pm \sqrt{48^2-4(-16)(288)}}{2(-16)}[/tex]

[tex]$t=\frac{-48\pm \sqrt{2304+18432}}{-32}[/tex]

[tex]$t=\frac{-48\pm \sqrt{20736}}{-32}[/tex]

[tex]$t=\frac{-48\pm144}{-32}[/tex]

Now, write find two t's using plus and minus operation.

[tex]$t=\frac{-48+144}{-32},\ \ t=\frac{-48-144}{-32}[/tex]

[tex]$t=\frac{96}{-32},\ \ t=\frac{-192}{-32}[/tex]

t = –3 (or)   t = 6

We cannot write time is negative. so neglect t = –3.

Therefore t = 6.

Hence 6 sec can take penny to strike the ground.

PLEASE HELP ME!!! there's an equation: y × 6 for y = 2/3. what the heck is the y?!​

Answers

Answer:

y equals 2/3. u have to do 2/3 ×6 I'm pretty sure

On Saturday sally works 8.25 hours and earns $6.50 an hour. Michelle work 6.75 hours and earns $8.95 an hour. Who earns more? How much more?

Answers

Answer:

Sally y= (8.25)(6.5)= $53.63

Michelle y = (6.75)(8.95)= $60.41

Michelle earns more

60.41-53.63= $6.78

Jack has $12,000 to invest and wants to earn 7.5% interest per year. He will put some of the money into a savings account that earns 4% per year and the rest into a CD account that earns 9% per year. How much money should he put into each account?

Answers

Jack should invest $8400 in the CD account and $3600 in the savings account.

Step-by-step explanation:

Jack wants to earn 7.5% interest per year. That implies he wants to earn

7.5/100*12000 per year i.e $900 per year.

Lets assume he invests X amount in the savings account. That leaves 12000-X to be invested in the CD account.

That implies,

[tex]4/100*X + 9/100*(12000-X) = 900[/tex]

=> [tex](4X+108000-9X)/100 = 900[/tex]

=> [tex]-5X = 90000-1080000 = -18000[/tex]

=> X = 3600

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