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3 years ago

Please help!!! It’s surface area

Mathematics

1 answer:

Zina [86]3 years ago

6 0

Answer:

3466.64 (≈ 3467) cm²

Step-by-step explanation:

A = 2B + 2 sides and floor

A = 2 * (14 * 24) / 2 + 2 * (45 * √14² + 24²) + 45 * 14

A = 336 + 2500.64 + 630 = 3466.64 (≈ 3467)

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Electric charge is distributed over the disk x2 + y2 ≤ 16 so that the charge density at (x, y) is rho(x, y) = 2x + 2y + 2x2 + 2y

professor190 [17]

Answer:

Required total charge is $256\pi$ coulombs per square meter.

Step-by-step explanation:

Given electric charge is dristributed over the disk,

$x^2=y^2\leq 16$ so that the charge density at (x,y) is,

$\rho (x,y)=2x+2y+2x^2+2y^2$

To find total charge on the disk let Q be the total charge and $x=r\cos\theta,y=r\sin\theta$ so that,

$Q={\int\int}_Q\rho(x,y) dA$ where A is the surface of disk.

$=\int_{0}^{2\pi}\int_{0}^{4}(2x+2y+2x^2+2y^2)dA$

$=\int_{0}^{2\pi}\int_{0}^{4}(2r\cos\theta+2r\sin\theta+2r^2 \cos^{2}\theta+2r^2\sin^2\theta)rdrd\theta$

$=2\int_{0}^{2\pi}\int_{0}^{4}r^2(\cos\theta+\sin\theta)drd\theta+2\int_{0}^{2\pi}\int_{0}^{4}r^3drd\theta$

$=\frac{2}{3}\int_{0}^{2\pi}(\sin\theta+\cos\theta)\Big[r^3\Big]_{0}^{4}d\theta+2\int_{0}^{2\pi}\Big[\frac{r^4}{4}\Big]d\theta$

$=\frac{128}{3}\int_{0}^{2\pi}(\sin\theta+\cos\theta)d\theta+128\int_{0}^{2\pi}d\theta$

$=\frac{128}{3}\Big[\sin\theta-\cos\theta\Big]_{0}^{2\pi}+128\times 2\pi$

$=\frac{128}{3}\Big[\sin 2\pi-\cos 2\pi-\sin 0+\cos 0\Big]+256\pi$

$=256\pi$

Hence total charge is $256\pi$ coulombs per square meter.

3 0

3 years ago

Help me pleaseee someone

QveST [7]

Answer:

55°

Step-by-step explanation:

All triangles have a sum of 180°

180 - (35 + 90) = angle B

180 - (125) = angle B

55 = angle B

So, angle B has a measurement of 55°

6 0

3 years ago

Rewrite the the expression using as few terms as possible. X^2+5x+4x+20

Effectus [21]

Answer:

x^2 + 9x + 20

Step-by-step explanation:

x^2 + 5x + 4x + 20

x^2 + 9x + 20

all u have to do is combine liked terms

8 0

3 years ago

At many golf clubs, a teaching professional provides a free 10-minute lesson to new customers. A golf magazine reports that go

Airida [17]

Answer:

Step-by-step explanation:

a) The objective of the study is test the claim that the average gain in the green fees , lessons or equipment expenditure for participating golf facilities is less than $2,100 under the claim the null and alternative hypothesis are,

H₀ : μ = $2,100

H₀ : μ < $2,100

B) Suppose you selects α = 0.01

The probability that the null hypothesis is rejected when the average gain is $2,100 is 0.01

C) For α = 0.01

specify the rejection region of a large sample test

At the given level of significance 0.01 and the test is left-tailed then rejection level of a large-sample = < - 1.28

7 0

3 years ago

All real number that are less than or equal to -3 and greater thank or equal to -8

Mariulka [41]

Answer:

-3, -4, -5, -6, -7, -8

Step-by-step explanation:

Im not sure if that is what you are looking for or if you want x ≤ -3 and x ≥ -8

6 0

3 years ago