A is the answer for the sentence
Answer:
1000 Mega Ohms.
Explanation:
One mega Ohm is equal to 1,000,000 ohms, which is the resistance between two points of a conductor with one ampere of current at one volt. The mega Ohm is a multiple of the Ohm, which is the SI derived unit for electrical resistance. In the metric system, "mega" is the prefix for 10 raised to the power of 6.
Answer:
2800 [MPa]
Explanation:
In fracture mechanics, whenever a crack has the shape of a hole, and the stress is perpendicular to the orientation of such, we can use a simple formula to calculate the maximum stress at the crack tip
Where 
is the magnitude of he maximum stress at the tip of the crack, 
is the magnitude of the tensile stress, 
is 
the length of the internal crack, and 
is the radius of curvature of the crack.
We have:
![r_{c}=1.9*10^{-4} [mm]](https://tex.z-dn.net/?f=r_%7Bc%7D%3D1.9%2A10%5E%7B-4%7D%20%5Bmm%5D)
![l_{c}=3.8*10^{-2} [mm]](https://tex.z-dn.net/?f=l_%7Bc%7D%3D3.8%2A10%5E%7B-2%7D%20%5Bmm%5D)
![\sigma_{c}=140 [MPa]](https://tex.z-dn.net/?f=%5Csigma_%7Bc%7D%3D140%20%5BMPa%5D)
We replace:
![\sigma_{m} = 2*(140 [MPa])*(\frac{\frac{3.8*10^{-2} [mm]}{2}}{1.9*10^{-4} [mm]})^{0.5}](https://tex.z-dn.net/?f=%5Csigma_%7Bm%7D%20%3D%202%2A%28140%20%5BMPa%5D%29%2A%28%5Cfrac%7B%5Cfrac%7B3.8%2A10%5E%7B-2%7D%20%5Bmm%5D%7D%7B2%7D%7D%7B1.9%2A10%5E%7B-4%7D%20%5Bmm%5D%7D%29%5E%7B0.5%7D)
We get:
![\sigma_{m} = 2*(140 [MPa])*(\frac{\frac{3.8*10^{-2} [mm]}{2}}{1.9*10^{-4} [mm]})^{0.5}=2800 [MPa]](https://tex.z-dn.net/?f=%5Csigma_%7Bm%7D%20%3D%202%2A%28140%20%5BMPa%5D%29%2A%28%5Cfrac%7B%5Cfrac%7B3.8%2A10%5E%7B-2%7D%20%5Bmm%5D%7D%7B2%7D%7D%7B1.9%2A10%5E%7B-4%7D%20%5Bmm%5D%7D%29%5E%7B0.5%7D%3D2800%20%5BMPa%5D)
