An someone please help!

Find the work done by F= (x^2+y)i + (y^2+x)j +(ze^z)k over the following path from (4,0,0) to (4,0,4)

babunello [35]

$\vec F(x,y,z)=(x^2+y)\,\vec\imath+(y^2+x)\,\vec\jmath+ze^z\,\vec k$

We want to find $f(x,y,z)$ such that $\nabla f=\vec F$ . This means

$\dfrac{\partial f}{\partial x}=x^2+y$

$\dfrac{\partial f}{\partial y}=y^2+x$

$\dfrac{\partial f}{\partial z}=ze^z$

Integrating both sides of the latter equation with respect to $z$ tells us

$f(x,y,z)=e^z(z-1)+g(x,y)$

and differentiating with respect to $x$ gives

$x^2+y=\dfrac{\partial g}{\partial x}$

Integrating both sides with respect to $x$ gives

$g(x,y)=\dfrac{x^3}3+xy+h(y)$

Then

$f(x,y,z)=e^z(z-1)+\dfrac{x^3}3+xy+h(y)$

and differentiating both sides with respect to $y$ gives

$y^2+x=x+\dfrac{\mathrm dh}{\mathrm dy}\implies\dfrac{\mathrm dh}{\mathrm dy}=y^2\implies h(y)=\dfrac{y^3}3+C$

So the scalar potential function is

$\boxed{f(x,y,z)=e^z(z-1)+\dfrac{x^3}3+xy+\dfrac{y^3}3+C}$

By the fundamental theorem of calculus, the work done by $\vec F$ along any path depends only on the endpoints of that path. In particular, the work done over the line segment (call it $L$ ) in part (a) is

$\displaystyle\int_L\vec F\cdot\mathrm d\vec r=f(4,0,4)-f(4,0,0)=\boxed{1+3e^4}$

and $\vec F$ does the same amount of work over both of the other paths.

In part (b), I don't know what is meant by "df/dt for F"...

In part (c), you're asked to find the work over the 2 parts (call them $L_1$ and $L_2$ ) of the given path. Using the fundamental theorem makes this trivial:

$\displaystyle\int_{L_1}\vec F\cdot\mathrm d\vec r=f(0,0,0)-f(4,0,0)=-\frac{64}3$

$\displaystyle\int_{L_2}\vec F\cdot\mathrm d\vec r=f(4,0,4)-f(0,0,0)=\frac{67}3+3e^4$

8 0

3 years ago

Rebeca spent $32.55 for a photo album and three identical candles. The photo album cost $17.50 and the sales tax was $1.55. How

Marina86 [1]

Answer: $4.50 per candle

Step-by-step explanation:

$32.55 - $17.50 - $1.55 = $13.50 for all the candles

To find the price of a single candle we divide our answer by 3

13.50/3 = $4.50

3 0

3 years ago

Evaluate this fraction 7 2/3 x 10 1/2

Slav-nsk [51]

The answer is 34 1/2

6 0

3 years ago

Are this two triangles similar?

Alex73 [517]

<h3>Answer: </h3><h3>Yes, the triangles are similar</h3><h3>AC = 6</h3>

======================================================

Explanation:

Focus on triangle ABC. Let's find the missing angle

A+B+C = 180

113+B+22 = 180

B+135 = 180

B = 180-135

B = 45

Between the triangles, have two pairs of angles that are congruent

A = D = 113

B = E = 45

Which is enough to prove the triangles are similar through the angle angle (AA) similarity theorem. This must mean that C = F = 22

Since we have A pair with D, and B pair with E, this means that $\triangle ABC \sim \triangle DE F$

The order of the letters is important so we know how the angles pair up. The first letters pair up together, the second letters pair up, and so on.

Consequently, this means sides BC and EF pair up and AC and DF pair up

We can then say...

BC/EF = AC/DF

18/12 = x/4

18*4 = 12*x

72 = 12x

12x = 72

x = 72/12

x = 6

AC = 6

5 0

3 years ago

A football team loses 3 yards in 3 consecutive plays. What’s the total yardage gained?

Anni [7]

-3×3=-9 so gain is 0

4 0

3 years ago