Input Energy ---> Output Energy

The flow curve for a certain metal has parameters: strain-hardening

ZanzabumX [31]

Answer:(a) $45,300.24 lb/in/^2$

(b)0.255

Explanation:

Given

Strain hardening exponent(n)=0.22

Strength coefficient(k) $=54000 lb/in/^2$

and we know

$\sigma =k\left ( \epsilon \right )^n$

where

$sigma =true\ stress$

$\epsilon =true\ strain$

(a)True strain=0.45

$\sigma =54000\times 0.45^{0.22}$

$\sigma =45,300.24 lb/in^2$

(b)true stress $=40,000 lb/in^2$

$40000=54000\times \epsilon ^{0.22}$

$\epsilon ^{0.22}=0.7407$

$\epsilon =0.7407^{4.5454}=0.255$

3 0

2 years ago

Calculate the number of vacancies per cubic meter at 1000∘C for a metal that has an energy for vacancy formation of 1.22 eV/atom

Makovka662 [10]

Answer:

C

Explanation:

N = Na.P/A------(1)

Na = avogadro's number = 6.02210²³

P = density

A = atomic weight of metal

When we substitute into equation 1 above we get

1.0x10²⁹atoms/m³

From here we calculate the number of vacancies

T = 1000⁰c = 1273K

The formula to use is

Nv= Nexo(Qt/K.T) -----(2)

Qt = 1.22eV

K = Boltzmann's constant = 8.6210x10^-5

When we substitute values into equation 2

We get Nv = 1.49 x 10²⁴m-3

Therefore option c is correct

Check attachment for a more detailed calculation of this question

6 0

3 years ago

10. True or False: You should select your mechanic before you experience vehicle failure.

ra1l [238]

Answer:

True

Explanation:

Always see a professional if you have any issues that is not in your scope of practice

7 0

3 years ago

Read 2 more answers

Two mass streams of the same ideal gas are mixed in a steady-flow chamber while receiving energy by heat transfer from the surro

loris [4]

Answer:

(a)The final temperature of mixture is T₃ =m₁T₁/m₃+ m₂T₂/m₃ + Qin/m₃Cp

(b) The final volume is V₃ =V₁ + V₂ + RQin/P₃Cp

(c) The volume flow rate at exit is V₃ =V₁ + V₂

Explanation:

Solution

Now

The system comprises of two inlets and on exit.

Mass flow rate enthalpy of fluid from inlet -1 be m₁ and h₁

Mass flow rate enthalpy of fluid from inlet -2 be m₂ and h₂

Mass flow rate enthalpy of fluid from exit be m₃ and h₃

Mixing chambers do not include any kind of work (w = 0)

So, both the kinetic and potential energies of the fluid streams are usually negligible (ke =0, pe =0)

(a) Applying the mass balance of mixing chamber, min = mout

Applying the energy balance of mixing chamber,

Ein = Eout

min hin =mout hout

miCpT₁ + m₂CpT₂ +Qin =m₃CpT₃

T₃ = miCpT₁/m₃CpT₃ + m₂CpT₂/m₃CpT₃ + Qin/m₃CpT₃ +

T₃ =m₁T₁/m₃+ m₂T/m₃ + Qin/m₃Cp

The final temperature of mixture is T₃ =m₁T₁/m₃+ m₂T₂/m₃ + Qin/m₃Cp

(b) From the ideal gas equation,

v =RT/PT

v₃ = RT₃/P₃

The volume flow rate at the exit, V₃ =m₃v₃

V₃ = m₃ RT₃/P₃

Substituting the value of T₃, we have

V₃=m₃ R/P₃ (=m₁T₁/m₃+ m₂T₂/m₃ + Qin/m₃Cp)

V₃ = R/P₃ (m₁T₁+ m₂T₂ + Qin/Cp)

Now

The mixing process occurs at constant pressure P₃=P₂=P₁.

Hence V₃ becomes:

V₃=m₁RT₁/P₁ +m₂RT₂/P₂ + RQin/P₃Cp

V₃ =V₁ + V₂ + RQin/P₃Cp

Therefore, the final volume is V₃ =V₁ + V₂ + RQin/P₃Cp

(c) Now for an adiabatic mixing, Qin =0

Hence V₃ becomes:

V₃ =V₁ + V₂ + r * 0/P₃Cp

V₃ =V₁ + V₂ + 0

V₃ =V₁ + V₂

Therefore the volume flow rate at exit is V₃ =V₁ + V₂

8 0

3 years ago

Suppose that the time (in hours) required to repair a machine is an exponentially distributed random variable with parameter ???

Andrej [43]

We need to define the variables,

So,

$F_x (x) = 1-e^{-\lambda x}\\F_x (x) = 1-e^{-0.5x}$

Therefore, the probability that the repair time is more than 4 horus can be calculate as,

$P(x>4)=1-P(x4)= 1-F_x(4)\\P(x>4) = 1-e^{-0.5*4}\\P(x>4) = 1-0.98\\P(x>4) = 0.018$

The probability that the repair time is more than 4 hours is 0.136

b) The probability that repair time is at least 12 hours given that the repair time is more than 7 hoirs is calculated as,

$P(x\geq 12|x>7)=P(X\geq7+5|x>7)\\P(x\geq12|x>7)=P(X\geq5)\\P(x\geq12|x>7)=1-P(x\leq 5)\\P(x\geq12|x>7)=1-e^{-0.5(2)}$

$P(x\geq 12|x>7)=0.6321$

The probability that repair time is at least 12 hours given that the repair time is more than 7 hours is 0.63

3 0

3 years ago