The slope is -1: (-4, -1)

If the acceleration of an object is given by dv/dt = −2v, Find the position function s(t) if v(0) = 7 and s(0) = 0.

kirill [66]

Answer:

Step-by-step explanation:

Given that acceleration of an object is

$\frac{dv}{dt} =-2v\\\frac{dv}{v} =-2dt\\ln v = -2t+C\\$

is the solution to the differential equation

Since v(0) =7

we get ln 7 = C

Hence $lnv = -2t+ln 7\\v=7e^{-2t}$

since velocity is rate of change of distance s we have

$v=\frac{ds}{dt} =7e^{-2t}\\s= [tex]s(t) =\frac{-7}{2} (e^{-2t})+C)[$

substitute t=0 and s=0

$C=7/2$

So solution for distance is

$s(t) =\frac{-7}{2} (e^{-2t}-1)$

4 0

3 years ago

The Thompson family is buying a car that can travel 70 miles

gogolik [260]

Answer:

The car gets 35 miles per gallons.

Step-by-step explanation:

4 0

3 years ago

In order to solve the following system of equations by addition, which of the

Pavlova-9 [17]

Answer:

Multiply the top equation by -3 and the bottom equation by 2

Step-by-step explanation:

Given system of equations:

$\begin{cases}4x-2y=7\\3x-3y=15 \end{cases}$

To solve the given system of equations by addition, make one of the variables in both equations sum to zero. To do this, the chosen variable must have the same coefficient, but it should be negative in one equation and positive in the other, so that when the two equations are added together, the variable is eliminated.

To eliminate the variable y:

Multiply the top equation by -3 to make the coefficient of the y variable 6:

$\implies -3(4x-2y=7) \implies -12x+6y=-21$

Multiply the bottom equation by 2 to make the coefficient of the y variable -6:

$\implies 2(3x-3y=15) \implies 6x-6y=30$

Add the two equations together to eliminate y:

$\begin{array}{l r r}& -12x+6y= &-21\\+ & 6x-6y= & 30\\\cline{1-3}& -6x\phantom{))))))} = & 9\end{array}$

Solve for x:

$\implies -6x=9$

$\implies x=-\dfrac{9}{6}=-\dfrac{3}{2}$

Substitute the found value of x into one of the equations and solve for y:

$\implies 3\left(-\dfrac{3}{2}\right)-3y=15$

$\implies -\dfrac{9}{2}-3y=15$

$\implies -3y=\dfrac{39}{2}$

$\implies y=-\dfrac{39}{2 \cdot 3}$

$\implies y=-\dfrac{13}{2}$

Learn more about systems of equations here:

brainly.com/question/27868564

brainly.com/question/27520807

3 0

2 years ago

Read 2 more answers

A theatre group sold a total of 440 tickets for a show, making a total of $3940. Each regular ticket cost $5, each premium ticke

valentina_108 [34]

Answer: 330 regular tickets, 46 premium tickets and 64 elite tickets were sold.

Step-by-step explanation:

Let x represent the number of regular tickets that were sold.

Let y represent the number of premium tickets that were sold.

Let z represent the number of elite tickets that were sold.

The theatre group sold a total of 440 tickets for the show. It means that

x + y + z = 440- - - - - - - - - -1

Each regular ticket cost $5, each premium ticket cost $15, and each elite ticket cost $25. The total amount made from the show was $3940. It means that

5x + 15y + 25z = 3940- - - - - - - - - 2

The number of regular tickets was three times the number of premium and elite tickets combined. It means that

x = 3(y + z)

x = 3y + 3z

Substituting x = 3y + 3z into equation 1 and equation 2, it becomes

3y + 3z + y + z = 440

4y + 4z = 440- - - - - - - - - - - - -3

5(3y + 3z) + 15y + 25z = 3940

15y + 15z + 15y + 25z = 3940

30y + 40z = 3940 - - - - - - - - - - 4

Multiplying equation 3 by 10 and equation 4 by 1, it becomes

40y + 40z = 4400

30y + 40z = 3940

Subtracting, it becomes

10y = 460

y = 460/10

y = 46

Substituting y = 46 into equation 3, it becomes

4 × 46 + 4z = 440

184 + 4z = 440

4z = 440 - 184

4z = 256

z = 256/4

z = 64

x = 3(y + z) = 3(46 + 64)

x = 330

4 0

3 years ago

Can someone help me out

LiRa [457]

3/196

Step-by-step explanation:

multiply everything

5 0

3 years ago