Asked by Anon

a)The Young's modulus for a material is 5.0*10^10 N/m2. The material is stretched to a strain of 4.0*10^-3. How much elastic energy will be expended? (Express your answer in J/m3)

Knowing that the energy associated with the formation of 1 mole of vacancies in copper (Cu) is 104 kJ, determine the vacancy density (nv/cm3) in Cu at 1366 K. Assume the pre-exponential factor is one.


Can someone help me with those questions? I can help with the rest!!
Answered by koala
Hi I am working on it. Meanwhile Can you help me with the 3th and 4th questions about the graphics?
Answered by Anon
3//1.13 ev
semiconductor

4//4th option
n-type
4th option
intrinsic
Answered by chimi
Hi can you help me with first part of 1st question .
answer of 2nd part is 189
Answered by Mx
can u help me with the formula of Cu bsc me temperature is 1056 plssssssssssssssssss help
Answered by Mx
Determine for solid manganese (Mn) the following:

What is the atomic density (atoms/m) along the [110] direction of the Mn crystal?
What are the number of nearest neighbors around an atom in the Mn crystal?
Calculate the interplanar spacing (m) between {220} planes in the Mn crystal.
Answered by Anon
if someone help with those questions I'll post all the rest of answers
Answered by Nano
ΔHv=104,000J/6.02×10^23=1,7276*10^-19

nv/Ns=e^{(-1.7276*10^-19)/[(1.381×10^−23)*(1366)]}=Result

Use the result to substitute to:
nv/Ns*ρ*Avogadro number/Mw(Cu)
=
nv/Ns(result from above) * 8.94*( 6.02*10^23/63.546)
Answered by Nano
watch out that the formula is negative (on e), so it should be in the range of x*10^-4 or 10^-5!
And note, that I can not give you the right answer as I succeeded only on my third attempt :)
I need help with 11 and 12.
Answered by Anon
1- 7.36e-2
189
2-metal
Solid hydrogen has a half filled s-band
insulator
Solid helium has a filled s-band
3-1.13
semiconductor
4-Ionization of phosphorus requires some minimum temperature
n_type
The concentration of conduction electrons is fixed by the concetration of phosphorus
intrinsic
5-2.44e9
8
1.025e-10
6-1.8e-10
7-BCC
3.172
1.37
8- HELP !!!!!!!!!!!!!!!!!!!!!!!!!!
9-(for energy 104 kj and vacancy density 1366 K) 8924699659276140118.9689358889623
10-sample A
sample B
sample B
sample D
sample C
sample C
11-increase air flow on the bottom array
12-2.773e-2
13-2.58e16

Answered by Drew
The Young's modulus for a material is 8.0 x 1010 N/m2. The material is stretched to a strain of 9.0 x 10-3. How much elastic energy will be expended? (Express your answer in J/m3).

Answer: 3240000
Answered by Anon
@Drew can you give me the formula?
Answered by Drew
Ev= elastic strain energy per unit vol=?

Ev=(1/2)*Ey*E2(square)

Ey= 8.0*10e+10 N/m2

E= 9.0e-3 so square ->

E2= 8.1e-5
Answered by Anon
thanks
Answered by Anon
Did you find the last quetion of homework 11?
Answered by Drew
No, I didn't find that answer.
Answered by Mx
can u help me with the formula of Cu bsc me temperature is 1056 plssssssssssssssssss help
Answered by Drew
nv/Ns=A*e(-Hv/(KT))

K=1.381E-23
Hv= 104000/6.023e+23
A=1

vacancy density=(nv/Ns)*Cu density*(6.023e+23/Cu atomic weight)
Answered by Mx
thnks @ Drew :)
Answered by KS
Thanks Anon and Drew for the formula, I have other exams to prepare for so this was a life saver, I appreciate it truly. I however do not know how to calculate my result using exponents so can someone please solve for T=1373 K? I would be forever grateful. If I find the answers for the last few questions I will be sure to share it.
Answered by KS
oops I reset it, new value of T is 1091 K somebody help please :'(
Answered by KS
Never mind guys, alphawolfram did it for me :)~ any luck with the last three questions? Today is the deadline!
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