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2 years ago

Why do you think steeples and roofs might appear green, but a copper square does not?

1 answer:

8 0

Because the copper roofs, have been outside for a while and oxidization has occurred.
When metals become oxidized they rust, but when copper becomes oxidized, it turns greenish.
So copper roofs oxidize and turn green from being outside and a copper square doesn’t if it’s inside.

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Fghgfgfgfftftftft ttcc

Ganezh [65]

Answer:

ybbbbgbg

Explanation:

4 0

3 years ago

Read 2 more answers

A rigid vessel contains 3.98 kg of refrigerant-134a at 700 kPa and 60°C. Determine the volume of the vessel and the total intern

Arada [10]

<u>Answer:</u> The volume of the vessel is $0.1542m^3$ and total internal energy is 162.0 kJ.

<u>Explanation:</u>

To calculate the volume of water, we use the equation given by ideal gas, which is:

$PV=nRT$

or,

$PV=\frac{m}{M}RT$

where,

P = pressure of container = 700 kPa

V = volume of container = ? L

m = Given mass of R-134a = 3.98 kg = 3980 g (Conversion factor: 1kg = 1000 g)

M = Molar mass of R-134a = 102.03 g/mol

R = Gas constant = $8.31\text{L kPa }mol^{-1}K^{-1}$

T = temperature of container = $60^oC=[60+273]K=333K$

Putting values in above equation, we get:

$700kPa\times V=\frac{3980g}{102.03g/mol}\times 8.31\text{L kPa }\times 333K\\\\V=154.21L$

Converting this value into $m^3$ , we use the conversion factor:

$1m^3=1000L$

So, $\Rightarrow (\frac{1m^3}{1000L})\times 154.21L$

$\Rightarrow 0.1542m^3$

To calculate the internal energy, we use the equation:

$U=\frac{3}{2}nRT$

or,

$U=\frac{3}{2}\frac{m}{M}RT$

where,

U = total internal energy

m = given mass of R-134a = 3.98 kg = 3980 g (Conversion factor: 1kg = 1000g)

M = molar mass of R-134a = 102.03 g/mol

R = Gas constant = $8.314J/K.mol$

T = temperature = $60^oC=[60+273]K=333K$

Putting values in above equation, we get:

$U=\frac{3}{2}\times \frac{3980g}{102.03g/mol}\times 8.314J/K.mol\times 333K\\\\U=161994.6J$

Converting this into kilo joules, we use the conversion factor:

1 kJ = 1000 J

So, 161994.6 J = 162.0 kJ

Hence, the volume of the vessel is $0.1542m^3$ and total internal energy is 162.0 kJ.

6 0

3 years ago

Which defines health?

NARA [144]

I mean this is pretty obvious it's D. life expectancy is sort of close but not really. B is close too but it's not it bc that's not what health is. you could be over weight and not be sick and it still isn't healthy. and C isn't close at all. hope this helps, have an amazing day :)

7 0

3 years ago

Choose all the answers that apply. Sound _____. travels in transverse waves requires a medium to travel through travels most slo

kari74 [83]

Answer: Option (a) is the correct option.

Explanation:

In order to travel, sound does need a medium. The more closer the particles of a medium, the better sound can travel through it. Therefore, in solids sound travels very quickly because in solids particles are closer to each other. As a result, they can easily transmit the energy from one particle to another.

Thus, it becomes easier for sound to travel through it. On the other hand, in solids sound can travel in both longitudinal and transverse waves.

Hence, out of the given options, sound travels in transverse waves requires a medium to travel through is the correct option.

3 0

3 years ago

What are the strengths and limitations of a cell?

Dmitry [639]

Cells have limitations, if the cell is stronger it targets other cells , when a cell is weak it possibly mean it’s disease.

4 0

3 years ago