Help now plz just help plzzz

A bucket that weighs 4lband a rope of negligible weight are used todraw water from a well that is 80ftdeep. The bucket is filled

liq [111]

Answer:

Workdone = 3200 lb.ft

Step-by-step explanation:

We are told that the bucket is filled with 40 lb of water but water leaks out of a hole in the bucket at a rate of 0.2lb/s

Thus,

Weight of water at any given time (t) would be;

w(t) = 40 - 0.2t - - - - (1)

We are told the bucket is pulled up at a rate of 2ft/s.

Thus, height at time (t); y = 0 + 2t = 2t

Since y = 2t,

Then,t = y/2

Put y/2 for t in eq 1

Thus; w(y) = 40 - 0.2(y/2)

w(y) = 40 - 0.1y

Now, at y = 80 ft, we have;

w(80) = 40 - 0.1(80)

w(80) = 40 - 8 = 32 lb

Since 32 lbs are left, it means there is always water in the bucket.

Thus, work done is;

W = 80,0[∫(Total weight).dy]

W = 80,0[∫[(weight of rope) + (weight of bucket) + (weight of water)]dy]

W = 80,0[∫[0 + 4 + 40 - 0.1y]dy]

Integrating, we have;

W = [44y - y²/20] at boundary of 80 and 0

So,

W = [44(80) - 80²/20] - [0 - 0²/20]

W = 3200 lb.ft

8 0

3 years ago

G find the area of the surface over the given region. use a computer algebra system to verify your results. the sphere r(u,v) =

Svetach [21]

Presumably you should be doing this using calculus methods, namely computing the surface integral along $\mathbf r(u,v)$ .

But since $\mathbf r(u,v)$ describes a sphere, we can simply recall that the surface area of a sphere of radius $a$ is $4\pi a^2$ .

In calculus terms, we would first find an expression for the surface element, which is given by

$\displaystyle\iint_S\mathrm dS=\iint_S\left\|\frac{\partial\mathbf r}{\partial u}\times\frac{\partial\mathbf r}{\partial v}\right\|\,\mathrm du\,\mathrm dv$

$\dfrac{\partial\mathbf r}{\partial u}=a\cos u\cos v\,\mathbf i+a\cos u\sin v\,\mathbf j-a\sin u\,\mathbf k$
$\dfrac{\partial\mathbf r}{\partial v}=-a\sin u\sin v\,\mathbf i+a\sin u\cos v\,\mathbf j$
$\implies\dfrac{\partial\mathbf r}{\partial u}\times\dfrac{\partial\mathbf r}{\partial v}=a^2\sin^2u\cos v\,\mathbf i+a^2\sin^2u\sin v\,\mathbf j+a^2\sin u\cos u\,\mathbf k$
$\implies\left\|\dfrac{\partial\mathbf r}{\partial u}\times\dfrac{\partial\mathbf r}{\partial v}\right\|=a^2\sin u$

So the area of the surface is

$\displaystyle\iint_S\mathrm dS=\int_{u=0}^{u=\pi}\int_{v=0}^{v=2\pi}a^2\sin u\,\mathrm dv\,\mathrm du=2\pi a^2\int_{u=0}^{u=\pi}\sin u$
$=-2\pi a^2(\cos\pi-\cos 0)$
$=-2\pi a^2(-1-1)$
$=4\pi a^2$

as expected.

6 0

2 years ago

Solve this please quickly

Volgvan

Answer:

1. m∠B=110°

2. 560 cm3

3. Numerical data

4. 2000 cm3

5. 50%

Step-by-step explanation:

1. The explanation of part 1 is given in the attachment.

2. Given dimensions : 10 cm, 8 cm, and 7 cm.

Let Length of cuboid =10 cm

breadth/width of cuboid =8 cm

height of cuboid = 7cm

Volume of cuboid = length *width* height

=( 10 *8*7) cm3

=(560) cm3

3. Age, Birth date and weight are the types/examples of "Numerical Data" because these all are describe in terms of numeric values.

4. 1 liter = 1000 cm3 or 1 cm3 = 0.001 liter

1.5 liters =(1.5*1000) cm3 = (15*100) =1500 cm3

1 dm3 =1000 cm3

0.35 dm3 = (0.35*1000) cm3 = (35*10) cm3 =350 cm3

Given expression: 1.5 litre + 0.35 dm3 + 150 cm3 = cm3

1500 cm3 + 350 cm3 +150 cm3 = 2000 cm3

5. If A=(1/2)B, then B : A = 50 %

Ratio: B : A

B : (1/2) B

1: (1/2)

50 % (The value of A is half of the value of B)

Download docx

6 0

2 years ago

Which graph shows the solution to the system of linear inequalities?

tangare [24]

Answer:

See below

Step-by-step explanation:

Given system:

y ≥ 2x + 1
y ≤ 2x – 2

The solution is the common area shaded by the inequalities.

The lines are parallel because of same slope.

Both lines are solid because of equal sign in both inequalities.

The first inequality has a y-intercept of 1 and shaded area is to the left of the line since the value of y is greater as x increases.

The second inequality has a y-intercept of -2 and shaded area is to the right of the line since the value of y is greater as x increases.

The matching graph is the second picture (or attached below) and there is no solution.

8 0

2 years ago

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Please help me dunduendjenbe!!! I beg u

Harman [31]

Answer:

y = 4/3x - 2, B is your answer

Step-by-step explanation:

Y intercept is the number next to slope(b).

The co efficient of x will be your slope so therefore the co efficient of x will be 4/3

y is always there because it will always be the dependent variable on the left side.

3 0

2 years ago

Read 2 more answers