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3 years ago

Help I don’t understand this question

Physics

1 answer:

7nadin3 [17]3 years ago

5 0

Metals
3/4 of the periodic table
Good conductors of heat and electricity
Malleable

Nonmetals
1/4 of the periodic table
Bad conductors of heat and electricity
Not bendable

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When was the first electric typewriter produced and by what company

LiRa [457]

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3 years ago

Two workers are sliding 300 kg crate across the floor. One worker pushes forward on the crate with a force of 400 N while the ot

almond37 [142]

Answer:

The kinetic coefficient of friction of the crate is 0.235.

Explanation:

As a first step, we need to construct a free body diagram for the crate, which is included below as attachment. Let supposed that forces exerted on the crate by both workers are in the positive direction. According to the Newton's First Law, a body is unable to change its state of motion when it is at rest or moves uniformly (at constant velocity). In consequence, magnitud of friction force must be equal to the sum of the two external forces. The equations of equilibrium of the crate are:

$\Sigma F_{x} = P+T-\mu_{k}\cdot N = 0$ (Ec. 1)

$\Sigma F_{y} = N - W = 0$ (Ec. 2)

Where:

$P$ - Pushing force, measured in newtons.

$T$ - Tension, measured in newtons.

$\mu_{k}$ - Coefficient of kinetic friction, dimensionless.

$N$ - Normal force, measured in newtons.

$W$ - Weight of the crate, measured in newtons.

The system of equations is now reduced by algebraic means:

$P+T -\mu_{k}\cdot W = 0$

And we finally clear the coefficient of kinetic friction and apply the definition of weight:

$\mu_{k} =\frac{P+T}{m\cdot g}$

If we know that $P = 400\,N$ , $T = 290\,N$ , $m = 300\,kg$ and $g = 9.807\,\frac{m}{s^{2}}$ , then:

$\mu_{k} = \frac{400\,N+290\,N}{(300\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)}$

$\mu_{k} = 0.235$

The kinetic coefficient of friction of the crate is 0.235.

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3 years ago

What type of electromagnetic radiation is being used in the picture?

pashok25 [27]

Answer: b i think

Explanation:

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3 years ago

A man has been guarding a house for one hour . Why is it not considered work in science

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2 years ago

Sheila eats an energy bar right before she goes on a run. What energy changes will occur in sheila as she runs after eating?

LiRa [457]

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2 years ago

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