All categories

3 years ago

Why did engineers need to design a sunshade for Mercury Messenger?

Chemistry

2 answers:

zloy xaker [14]3 years ago

8 0

The answer is so it didn't burn.

scoundrel [369]3 years ago

6 0

They designed one cause of the sun powerful radiant energy and thermal they needed to protect the satellite from being disintegrated when it gets close to the sun its also the closet plant to the sun MVEMJSUN is a mnemonic device I made up it means my very energetic mother just served us nachos or that's what I say and that is your answer bam

You might be interested in

Pulverized coal pellets, which may be approximated as carbon spheres of radius ro= 1 mm, are burned in a pure oxygen atmosphere

Ganezh [65]

Answer:

Explanation:

SO; If we assume that:

P should be the diffusion of oxygen towards the surface ; &

Q should be the diffusion of carbondioxide away from the surface.

Then the total molar flux of oxygen is illustrated by :

$Na,x = - cD_{PQ}\frac{dy_P}{dr} +y_P(NP,x + N_Q,x)$

where;

r is the radial distance from the center of the carbon particle.

Since ;

$N_P,x = - N_Q, x$ ; we have:

$Na,x = - cD_{PQ}\frac{dy_P}{dr}$

The system is not steady state and the molar flux is not independent of r because the area of mass transfer $4\pi r^{2}$ is not a constant term.

Therefore, using quasi steady state assumption, the mass transfer rate $4\pi r^{2}N_{P,x}$ is assumed to be independent of r at any instant of time.

$W_{P}=4\pi r^{2}N_{P,x}$

$W_{P}=-4\pi r^{2}cD_{PQ}\frac{dy_{P}}{dr}$

= constant

The oxygen concentration at the surface of the coal particle $yP,R$ will be calculated from the reaction at the surface.

The mole fraction of oxygen at a location far from pellet is 1.

Thus, separating the variables and integrating result into the following:

$W_{P}\int_{R}^{\infty} \frac{dr}{r^{2}}=-4\pi$

$r^{2}cD_{PQ}\int_{y_{P,R}}^{y_{P,\infty }}dy_{P}$

$-W_{P}\frac{1}{r}\mid ^{\infty }_{R}= -4\pi cD_{PQ}(y_{P,\infty }-y_{P,R})$

$=> W_{P}= - 4\pi cD_{PQ}(1-y_{P,R})R$

The mole of oxygen arrived at the carbon surface is equal to the mole of oxygen consumed by the chemical reaction.

$W_{P} = 4 \pi R^2R"$

$W_{P}= 4\pi R^{2}k_{1}"C_{O_{2}}\mid _{R}$

$W_{P}= 4\pi R^{2}k_{1}"c y _{P,R}$

$-4\pi cD_{PQ}(1-y_{P,R})R= - 4\pi R^{2}k_{1}"c y _{P,R}$

$y_{P,R}=\frac{D_{PQ}}{D_{PQ}+Rk_{1}}$

$y_{P,R}=\frac{1.7 \times 10^{-4}}{1.7\times 10^{-4}+10^{-3}\times 0.1}$

$\mathbf{= 0.631}$

Obtaining the total gas concentration from the ideal gas law; we have the following:

where;

R= $0.082m^3atm/kmolK$

$c=\frac{P}{RT} \\ \\ c=\frac{1}{0.082\times 1450} \\ \\ = 0.008405kmol/m^3$

The steady state $O_2$ molar consumption rate is:

$W_{P}= -4\pi cD_{PQ}(1-y_{P,R})R$

$W_{P}= -4\pi (0.008405)(1.7\times 10^{-4})(1-0.631)(10^{-3})$

$W_{P}= - 6.66\times 10^{-9}kmol/s$

5 0

3 years ago

Help please i’ll give extra points

joja [24]

Answer:

okay no problem

I will give

7 0

3 years ago

Imagine a cell with a semi-permeable membrane that is selective to K+ ions only. The internal solution contains 100 mM KCl and t

Scrat [10]

Answer:

Ek = (RT/zF)*ln ( [k+]o/[K+]i )

Explanation:

R = gas constant (8.31 J/Kmol)

T = Temperature (k)

F = Faraday constant (9.65 * 10exp4 coulomb/mole)

z = valence of the ion (1)

[k+]o = Extracellular K concentration in mM

[K+]i = Intracellular K concentration in mM

ln = logarithm with base e

7 0

3 years ago

Is A car traveling 33 km/h. accelerating

MArishka [77]

Answer:

where is the question?

Explanation:

5 0

3 years ago

Calculate the mass of 25.0 mL of ethanol

Kruka [31]

At STP, pure ethanol has density 0.789g/mL. 25 mL will have mass 25 (mL) * 0.789 (g/mL)=19.725 g. Round this to 19.7g for three significant figures.

(not fully sure if this is correct)

3 0

4 years ago