Answer:
0.16 micron per day
Explanation:
Given:
The initial crack length, a₁ = 0.1 micron = 0.1 × 10⁻⁶ m
Initial tensile stress, σ₁ = 120 MPa
Final stress = 30 MPa
now from Griffith's equation, we have
![\sigma=[\frac{G_cE}{\pi\ a}]^\frac{1}{2}](https://tex.z-dn.net/?f=%5Csigma%3D%5B%5Cfrac%7BG_cE%7D%7B%5Cpi%5C%20a%7D%5D%5E%5Cfrac%7B1%7D%7B2%7D)
where, 
Gc and E are the material constants
now, 
for the initial stage
  ........{1}
and for the final case
   ............{2}
on dividing 1 by 2, we get
![\frac{120}{30}=[\frac{a_2}{0.1\times10^{-6}}]^\frac{1}{2}](https://tex.z-dn.net/?f=%5Cfrac%7B120%7D%7B30%7D%3D%5B%5Cfrac%7Ba_2%7D%7B0.1%5Ctimes10%5E%7B-6%7D%7D%5D%5E%5Cfrac%7B1%7D%7B2%7D)
or
a₂ = 4² × 0.1 × 10⁻⁶ m
or
a₂ = 1.6 micron
Now,
the change from 0.1 micron to 1.6 micron took place in 10 days
therefore, the rate at which the crack is growing = 
or
average rate of change of crack = 0.16 micron per day
 
        
             
        
        
        
Answer:
what do u mean.
 
        
             
        
        
        
Answer:
There are 50 ASE certification tests, covering almost every imaginable aspect of the automotive repair and service industry.
Explanation:
yww <33
  
        
             
        
        
        
The expression of V(m³)=e^(t(s)) to make V in in³ and t in minutes is;
V(in³) = (¹/₆₁₀₂₄)a
We are given that;
Volume of microbial culture is observed to increase according to the formula;
V = e^(t)
where;
t is in seconds 
V is in m³
We want to now express V in in³ and t in minutes.
Now, from conversions;
1 m³ = 61024 in³
Also; 1 second = 1/60 minutes
according to formula for exponential decay, we know that;
V = ae^(bt)
Thus, we have;
61024V = ae^(¹/₆₀b(t(h))
V(in³) = (¹/₆₁₀₂₄)a
Read more about subject of formula at; brainly.com/question/790938
 
        
             
        
        
        
Answer:
Here are some cool ideas that you could do
-Zero fuel aircraft
-Advanced Space Propulsion Technologies
-Smart Automation and Blockchain
These are some things I've been working on for a few years lol, maybe you will have more luck