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3 years ago

Why is oil black and why does oil look black

Engineering

1 answer:

Rina8888 [55]3 years ago

4 0

Answer:While heat cycles cause oil to darken, soot causes oil to turn black

Explanation:

Most people associate soot with diesel engines, but gasoline engines can produce soot as well, particularly modern gasoline-direct-injection engines. ... Any finer filtration and the filter could catch dissolved additives in the motor oil

You might be interested in

Find the phasor form of:

mixer [17]

Answer:

$I=24.598\angle 50.377$

Explanation:

A tension or current expressed in cosine form and with a positive sign can be converted directly into a phasor. This is done by indicating the tension and the offset angle:

$Acos(10\omega t +\phi)=A\angle \phi$

So:

$i(t)=10cos(10t+63)+15cos(10t-42)=10\angle 63 + 15\angle42=I$

You can sum the phasors simply using a calculator, however, let's do it manually:

Let's find the rectangular form of each phasor using the next formulas:

$A=\sqrt{a^2+b^2} \\\phi=arctan(\frac{b}{a})$

For $10\angle 63$

$63=arctan(\frac{b}{a} )\\\\tan(63)=\frac{b}{a} \\\\b=a*tan(63)$

$10=\sqrt{a^2+(a*tan(63))^2} \\\\10^2=a^2+a^2*(tan(63))^2\\\\Solving\hspace{3}for\hspace{3}a\\\\a=\sqrt{\frac{100}{1+tan(63)^2} } =4.539904997\\\\and\hspace{3}b\\b=\sqrt{100-a^2} =8.910065242$

So:

$Z_1=a+bj=4.539904997+8.910065242j$

For $15\angle 42$

$42=arctan(\frac{b_2}{a_2} )\\\\tan(42)=\frac{b_2}{a_2} \\\\b_2=a_2*tan(42)$

$15=\sqrt{a_2^2+(a_2*tan(42))^2} \\\\15^2=a_2^2+a_2^2*(tan(42))^2\\\\Solving\hspace{3}for\hspace{3}a_2\\\\a_2=\sqrt{\frac{225}{1+tan(42)^2} } =11.14717238\\\\and\hspace{3}b_2\\\\b_2=\sqrt{225-a^2} =10.0369591$

So:

$Z_2=a_2+b_2j=11.14717238+10.0369591j$

Hence:

$Z_T=Z_1+Z_2=(4.539904997+11.14717238)+(8.910065242+10.0369591)j\\Z_T=15.68707738+18.94702434j$

Finally:

$I=\sqrt{15.68707738^2+18.94702434^2} \angle arctan (\frac{18.94702434}{15.68707738} )=24.598\angle 50.377$

7 0

3 years ago

What is the subtotal for the building materials in the bill? The subtotal should be the cost of the materials only. Don't add ta

Alexxx [7]

Answer:

Cost before adding taxes and incorporating variations

Explanation:

The sub-totals are basically sum of the cost from individual pages before including value added tax or any other tax depending with the state regulations. At this stage, contingencies and variation of prices are not considered. Therefore, the sub-total for building materials only include the materials on site or materials used as per the bill of quantities and certified by the engineer.

3 0

4 years ago

BCC lithium has a lattice parameter of 3.5089 3 10–8 cm and contains one vacancy per 200 unit cells. Calculate (a) the number of

Tanya [424]

(a) The number of vacancies per cubic centimeter is 1.157 X 10²⁰

(b) ρ = n X (AM) / v X Nₐ

<u>Explanation:</u>

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Given-

Lattice parameter of Li = 3.5089 X 10⁻⁸ cm

1 vacancy per 200 unit cells

Vacancy per cell = 1/200

(a)

Number of vacancies per cubic cm = ?

Vacancies/cm³ = vacancy per cell / (lattice parameter)³

Vacancies/cm³ = 1 / 200 X (3.5089 X 10⁻⁸cm)³

Vacancies/cm³ = 1.157 X 10²⁰

Therefore, the number of vacancies per cubic centimeter is 1.157 X 10²⁰

(b)

Density is represented by ρ

ρ = n X (AM) / v X Nₐ

where,

Nₐ = Avogadro number

AM = atomic mass

n = number of atoms

v = volume of unit cell

4 0

3 years ago

Why is it important to use the proper line types? ( In five sentences) pls i need help!! #enginering

Tanya [424]

Communication-each have different meanings because when you use the proper paper lines it will help you when you are older and now also it will help you in your drawing technique.(This question can help hope you will understand)

5 0

3 years ago

Not sure which one....

Airida [17]

I think downwards as that's how most saw's work.

4 0

3 years ago