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3 years ago

The atmosphere is divided into different layers, each with a different function. The stratosphere contains the ozone (O3).

Engineering

1 answer:

tangare [24]3 years ago

5 0

Answer:

a) At about 15 to 35 km from the Earth

b) It helps to absorb most of the ultraviolet rays from the sun, that is otherwise too dangerous here on Earth.

c) The depletion of the ozone layer is due to free radical catalysts, like nitric oxide (NO), nitrous oxide (N2O), hydroxyl (OH), but majorly due to atomic chlorine (Cl), and atomic bromine (Br) finding their way up to the the ozone layer.

d) The refrigeration processes and the aerosol aligned industrial processes, are the major culprits.

Explanation:

a) The ozone layer is lies in the lower portion of the stratosphere, from an height of about 15 to 35 kilometers from the surface of the Earth.

b) The ozone layer contains a large portion of ozone, a molecule of oxygen containing three oxygen atom bonded together. This ozone is created at this level by the action of ultraviolet radiation on an ordinary oxygen molecule, splitting it into two oxygen atom. Each of this oxygen atom then proceed to combine with another ordinary oxygen molecule, to form an ozone molecule. The ozone at this layer absorbs a large portion of the ultraviolet radiation from the sun.

c) The depletion of the ozone layer is due to the presence of some radical, that are able to survive up to the level of the ozone layer. At this level, ultraviolet radiation causes these these radicals to dissociate to give free bromine and chlorine mostly. This chlorine and bromine molecules breaks down the ozone molecules.

d) The various industrial processes includes refrigeration, and the aerosol industries that majorly releases the chlorofluorocarbons (CFCs) and bromofluorocarbons, which are the main culprits of ozone depletion.

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A gas is compressed from an initial volume of 0.42 m3 to a final volume of 0.12 m3. During the quasi-equilibrium process, the pr

Georgia [21]

Answer:

$W=-52 800\ \text{J}=-52.8\ \text{kJ}$

Explanation:

First I sketched the compression of the gas with the help of the given pressure change process relation. That is your pressure change due to change in volume.

To find the area underneath the curve (the same as saying to find the work done) you should integrate the given relation for pressure change:

$W=\int_{0.42}^{0.12}-1200V+500dV=-52.8\ \text{kJ}$

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3 years ago

Select the correct statement(s) regarding frequency modulation (FM). a. baseband amplitude changes (information) are captured as

mario62 [17]

<h3>All of the above statement are correct statement.</h3>

<u>Explanation</u>

Base-Band amplitude changes are captured as carrier wave wave frequency changes. In order to convert signal amplitude changes to changes in frequency, we need a device like VCO.

The bandwidth in the frequency domain increases with the change in carrier frequency.

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3 years ago

3. (a) (5 points) Suppose N packets arrive simultaneously to a link at which no packets are currently being transmitted or queue

Bezzdna [24]

Answer:

(N-1) × (L/2R) = (N-1)/2

Explanation:

let L is length of packet

R is rate

N is number of packets

then

first packet arrived with 0 delay

Second packet arrived at = L/R

Third packet arrived at = 2L/R

Nth packet arrived at = (n-1)L/R

Total queuing delay = L/R + 2L/R + ... + (n - 1)L/R = L(n - 1)/2R

Now

L / R = (1000) / (10^6 ) s = 1 ms

L/2R = 0.5 ms

average queuing delay for N packets = (N-1) * (L/2R) = (N-1)/2

the average queuing delay of a packet = 0 ( put N=1)

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3 years ago

If copper (which has a melting point of 1085°C) homogeneously nucleates at 849°C, calculate the critical radius given values of

____ [38]

Answer:

The critical radius is -1.30 nm

Explanation:

Temperature for homogenous nucleation of copper, $T_{H} = 849^{0} C = 849 + 273 = 1122 K$

Melting point of copper, $T_{cu} = 1085^{0} C = 1085 + 273 = 1358 K$

Latent heat of fusion, $H_{f} = -1.77 * 10^{9} J/m^{3}$

Surface free energy, $\gamma = 0.200 J/m^{2}$

Critical radius, r = ?

The formula for the critical radius is given by:

$r = \frac{2 \gamma T_{cu} }{H_{f}(T_{cu} - T_{H}) }$

$r = \frac{2 * 0.2*1358 }{(-1.77 * 10^{9}) (1358 - 1122) }$

$r = \frac{543.2 }{(-1.77 * 10^{9}) 236}\\r = -1.30 * 10^{-9} m\\r = -1.30 nm$

The critical radius is -1.30 nm

8 0

4 years ago

Rank the magnitudes of the diffusion coefficients from greatest to least for the following systems:(a) Cr in Fe at 600°C; (b) C

jek_recluse [69]

Answer:

Explanation:

The rank of the magnitude of the diffusion coefficient from greatest to least is as follows:

C in Fe at 900°C > Cr in Fe at 900°C > Cr in Fe at 600°C

Reason

C in Fe is an interstitial impurity while Cr in Fe is a substutional impurity.Therefore interstitial impurity occurs in C in Fe systems,while substutitional diffusion occurs in Cr in Fe system.Interstitial is much faster than substitutional diffusion hence the order

Also with increasing temperature magnitude of diffusion coefficient increases,due to the relation.

D = D₀exp(-Qd/RT)

Where D₀=Temperature independent per exponential

Qd= The activation energy for diffusion

R= Universal gas constant

T=absolute temperature

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3 years ago

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