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2 years ago

Is jewelry gold a compound or mixture?

Physics

2 answers:

USPshnik [31]2 years ago

7 0

I think it’s a mixture.

loris [4]2 years ago

4 0

Answer:

jewelry gold is a mixture.

Explanation:

it contains more than one element and its composition varies.

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Please help me on this l

eduard

Answer:

Explanation:

because

7 0

2 years ago

What fraction of all the electrons in a 25 mg water

mihalych1998 [28]

Answer:

$9.11\times 10^{-15}.$

Explanation:

The water droplet is initially neutral, it will obtain a 40 nC of charge when a charge of -40 nC is removed from the water droplet.

The charge on one electron, $\rm e=-1.6\times 10^{-19}\ C.$

Let the N number of electrons have charge -40 nC, such that,

$\rm Ne=-40\ nC\\\Rightarrow N=\dfrac{-40\ nC}{e}=\dfrac{-40\times 10^{-9}\ C}{-1.6\times 10^{-19}\ C}=2.5\times 10^{11}.$

Now, mass of one electron = $\rm 9.11\times 10^{-31}\ kg.$

Therefore, mass of N electrons = $\rm N\times 9.11\times 10^{-31}=2.5\times 10^{11}\times 9.11\times 10^{-31}=2.2775\times 10^{-19}\ kg.$

It is the mass of the of the water droplet that must be removed in order to obtain a charge of 40 nC.

Let it is m times the total mass of the droplet which is $25\ \rm mg = 25\times 10^{-6}\ kg.$

Then,

$\rm m\times (25\times 10^{-3}\ kg) = 2.2775\times 10^{-19}\ kg.\\m=\dfrac{2.2775\times 10^{-19}\ kg}{25\times 10^{-3}\ kg}=9.11\times 10^{-15}.$

It is the required fraction of mass of the droplet.

3 0

2 years ago

Question #5: Explain how a reflecting telescope is different from a refracting telescope. List the two different types of reflec

Anni [7]

The main component in a reflecting telescope is a mirror where the light will bounce off and is then focused into a smaller area. In contrast, a refracting telescope uses lenses that focus the light as it travels towards the other end.

Two different types of reflecting telescopes are:

1.Cassegrain reflector

2.Newtonian telescope

Explanation:

The distinction between the two is in how they manipulate the incoming light in order to magnify the image. The main component in a reflecting telescope is a mirror where the light will bounce off and is then focused into a smaller area.
Key advantage of reflecting telescopes is how big you can make them. With lenses, the maximum size is limited to about one meter, largely because of the problems stated above as well as the skyrocketing costs.
The Newtonian telescope, also called the Newtonian reflector, is a type of reflecting telescope invented Sir Isaac Newton, using a concave primary mirror and a flat diagonal secondary mirror. The Newtonian telescope's simple design has made it very popular with amateur telescope makers.
The Cassegrain reflector is a combination of a primary concave mirror and a secondary convex mirror, often used in optical telescopes and radio antennas, the main characteristic being that the optical path folds back onto itself, relative to the optical system's primary mirror entrance aperture.

6 0

2 years ago

Space Station Suppose a space-station is designed in s shape of a torus such as the one depicted in Stanley Kubrick's "2001: A s

yaroslaw [1]

Answer:

w = 3.2 rev / min

Explanation:

For this exercise we will use the centrine acceleration equal to the acceleration of gravity

a = v² / r

Angular and linear variables are related.

v = w r

Let's replace

a = w² r = g

w = √ g / r

r = d / 2

r = 175/2 = 87.5 m

w = √( 9.8 / 87.5)

w = 0.3347 rad / s

Let's reduce to rotations per min

w = 0.3347 rad / s (1 rov / 2pi rad) (60 s / 1 min)

w = 3.2 rev / min

Suppose the space station rotates counterclockwise, we have two possibilities for the car

The first car turns counterclockwise (same direction of the station

$v_{c}$ = $w_{c}$ r

[texwv_{c}[/tex] = $v_{c}$ / r

[texwv_{c}[/tex] = 25.0 / 87.5

[texwv_{c}[/tex] = 0.286 rad / s

When the two rotate in the same direction their angular speeds are subtracted

w total = w -[texwv_{c}[/tex]

w total = 0.3347 - 0.286

w total= 0.487 rad / s

The car goes in the opposite direction of the station the speeds add up

w = 0.3347 + 0.286

w = 0.62 rad / s

From this values we can see that the person feels a variation of the acceleration of gravity, feels that he has less weight when he goes in the same direction of the season and that his weight increases when he goes in the opposite direction to the season.

3 0

3 years ago

SOMEONE HELP PLEASE SORRY

evablogger [386]

Answer:

Just red light is reflected. Even if you shine a red laser at a blue piece of paper, only red light is reflected. ... The dot you see will probably always be red. If you do this in a bright room, you might trick yourself.

Explanation:

3 0

2 years ago