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2 years ago

Which of the following non-metals is used as a lubricant in powdered form?

Physics

1 answer:

blondinia [14]2 years ago

5 0

Answer:

Graphite.

Explanation:

Graphite:<em> "a gray crystalline allotropic form of carbon which occurs as a mineral in some rocks and can be made from coke. It is used as a solid lubricant, in pencils, and as a moderator in nuclear reactors."</em>

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Lithium is more active than aluminium<br> A.True<br> B.false

WITCHER [35]

A:True because Lithium is the lighest solid and metal and the third lightest element.

5 0

3 years ago

Read 2 more answers

In the most common isotope of Hydrogen the nucleus is made out of a single proton. When this Hydrogen atom is neutral, a single

FinnZ [79.3K]

Answer:

The ratio of electric force to the gravitational force is $2.27\times 10^{39}$

Explanation:

It is given that,

Distance between electron and proton, $r=4.53\ A=4.53\times 10^{-10}\ m$

Electric force is given by :

$F_e=k\dfrac{q_1q_2}{r^2}$

Gravitational force is given by :

$F_g=G\dfrac{m_1m_2}{r^2}$

Where

$m_1$ is mass of electron, $m_1=9.1\times 10^{-31}\ kg$

$m_2$ is mass of proton, $m_2=1.67\times 10^{-27}\ kg$

$q_1$ is charge on electron, $q_1=-1.6\times 10^{-19}\ kg$

$q_2$ is charge on proton, $q_2=1.6\times 10^{-19}\ kg$

$\dfrac{F_e}{F_g}=\dfrac{kq_1q_2}{Gm_1m_2}$

$\dfrac{F_e}{F_g}=\dfrac{9\times 10^9\times (1.6\times 10^{-19})^2}{6.67\times 10^{-11}\times 9.1\times 10^{-31}\times 1.67\times 10^{-27}}$

$\dfrac{F_e}{F_g}=2.27\times 10^{39}$

So, the ratio of electric force to the gravitational force is $2.27\times 10^{39}$ . Hence, this is the required solution.

3 0

3 years ago

Find the acceleration of the blocks when the system is released. The coefficient of kinetic friction is 0.4, and the mass of eac

grin007 [14]

Answer:

a = 4.9(1 - sinθ - 0.4cosθ)

Explanation:

Really not possible without a complete setup.

I will ASSUME that this an Atwood machine with two masses (m) connected by an ideal rope passing over an ideal pulley. One mass hangs freely and the other is on a slope of angle θ to the horizontal with coefficient of friction μ. Gravity is g

F = ma

mg - mgsinθ - μmgcosθ = (m + m)a

mg(1 - sinθ - μcosθ) = 2ma

½g(1 - sinθ - μcosθ) = a

maximum acceleration is about 2.94 m/s² when θ = 0

acceleration will be zero when θ is greater than about 46.4°

8 0

3 years ago

Define in own words.

nevsk [136]

Antioxidant are compounds found in foods..they help to prevent damage of the cell

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3 years ago

Fill in the appropriate values for each blank as it refers to ATOM 1. The number of protons present in ATOM 1 is _________.

wlad13 [49]

3, protons are positive and there are 3 positive atoms visible

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3 years ago