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2 years ago

An engineer is planning a new water pipe installation. The circular pipe has a diameter of d=20cm.

1 answer:

6 0

We know that
the area A of the circular cross section of the pipe is
A=pi*r²
D=20 cm------------- > r=D/2=20/2=10 cm
then
A=pi*10²=100*pi cm²

the answer is A=100*pi cm²

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vivado [14]

D. Expenses for a birthday party are not a fixed expense.

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2 years ago

For questions 10-11 if l || m, find the values of x and y.

klemol [59]

Answer:

10) 9x - 2° = 5x + 54° (corresponding angles are equal)

9x - 5x = 54 + 2

4x = 56

x = 56/4

x = 14°

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2 years ago

likoan [24]

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4 0

3 years ago

Read 2 more answers

PLEASE SHOW WORK

CaHeK987 [17]

(C)

Step-by-step explanation:

The volume of the conical pile is given by

$V = \dfrac{\pi}{3}r^2h$

Taking the derivative of V with respect to time, we get

$\dfrac{dV}{dt} = \dfrac{\pi}{3}\dfrac{d}{dt}(r^2h)$

$\:\:\:\:\:\:\:= \dfrac{\pi}{3}\left(2rh\dfrac{dr}{dt} + r^2\dfrac{dh}{dt}\right)$

Since r is always equal to h, we can set

$\dfrac{dr}{dt} = \dfrac{dh}{dt}$

so that our expression for dV/dt becomes

$\dfrac{dV}{dt} = \dfrac{\pi}{3}\left(3r^2\dfrac{dh}{dt}\right)$

$\:\:\:\:\:\:\:= \pi r^2\dfrac{dh}{dt}$

Solving for dh/dt, we get

$\dfrac{dh}{dt} = \dfrac{1}{\pi r^2}\dfrac{dV}{dt}$

$\:\:\:\:\:\:\:= \dfrac{1}{9\pi\:\text{m}^2}(36\:\text{m}^3\text{/s})$

$\:\:\:\:\:\:\:= \dfrac{4}{\pi}\:\text{m/s}$

7 0

2 years ago

Evaluate the expression 2ab 3+ 6a 3 - 4ab2 when a=2 and b=4.<br> a.176<br> b.180<br> c.215<br> d.216

Tom [10]

The first step for solving this expression is to insert what a and b stand for into the expression. This will change the expression to the following:
2(2)(4)³ + 6(2)³ - 4(2)(4)²
Now we can start solving this by factoring the expression
2(2 × 4³ + 3 × 2³ - 4 × 4²)
Write 4³ in exponential form with a base of 2.
2(2 × $2^{6}$ + 3 × 2³ - 4 × 4²)
Calculate the product of -4 × 4².
2(2 × $2^{6}$ + 3 × 2³ -4³)
Now write 4³ in exponential form with a base of 2.
2(2 × $2^{6}$ + 3 × 2³ - $2^{6}$ )
Collect the like terms with a base of 2.
2( $2^{6}$ + 3 × 2³)
Evaluate the power of 2³.
2( $2^{6}$ + 3 × 8)
Evaluate the power of $2^{6}$ .
2(64 + 3 × 8)
Multiply the numbers.
2(64 + 24)
Add the numbers in the parenthesis.
2 × 88
Multiply the numbers together to find your final answer.
176
This means that the correct answer to your question is option A.
Let me know if you have any further questions.
:)

5 0

2 years ago