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
![120=[\frac{G_cE}{\pi\ (0.1\times10^{-6}}]^\frac{1}{2}](https://tex.z-dn.net/?f=120%3D%5B%5Cfrac%7BG_cE%7D%7B%5Cpi%5C%20%280.1%5Ctimes10%5E%7B-6%7D%7D%5D%5E%5Cfrac%7B1%7D%7B2%7D)
........{1}
and for the final case
![30=[\frac{G_cE}{\pi\ a_2}]^\frac{1}{2}](https://tex.z-dn.net/?f=30%3D%5B%5Cfrac%7BG_cE%7D%7B%5Cpi%5C%20a_2%7D%5D%5E%5Cfrac%7B1%7D%7B2%7D)
............{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
The available options are:
a. Want for a television set
b. Want for medical attention
c. Want for friendship
d. Want for new clothing
Answer:
Want for friendship
Explanation:
Given that economic want is what humans desire to have or possess such that they pay money to acquire them.
Hence, from the available options "want for friendship " is not economic want because it can't be bought with money, while other options can be bought with money or monetary transaction.
Answer:
the answer is attached with required units.
Explanation:
Answer:
Option A
Explanation:
We know that ions are present in hydrogen-air flame and when the burning of an organic compound takes place in this flame more ions are produced in the flame.
Thus when we apply a voltage across this flame, the ion collector plate attracts the all the ions in the flame.
The presence of organic compounds increases the voltage across the hydrogen ion flame produced at the ion collector increases and as the voltage increases, the detection of the organic compound can be made in turn.
Thus flame ionization detector clearly responds to the variation in the collection of ions or electrons in a flame.
The function if I’m not correct just text me but 3
