Answer:
It is known as asymmetric key cryptography it is also called public key cryptography.
Explanation:
Asymmetric key cryptography method makes use of two keys.One is used for encryption and the second one for decryption. The public key serves to encrypt plain text or verify a digital signature, while the private key is used to decrypt or decipher the encrypted text or to create a digital signature.
Answer:
rate of recrystallization = 4.99 × 10⁻³ min⁻¹
Explanation:
For Avrami equation:
![y = 1-e ^{(-kt^n)} \\ \\ e^{(-kt^n)} = 1-y\\ \\ -kt^n = In(1-y) \\ \\ k = \dfrac{-In(1-y)}{t^n}](https://tex.z-dn.net/?f=y%20%3D%201-e%20%5E%7B%28-kt%5En%29%7D%20%5C%5C%20%5C%5C%20e%5E%7B%28-kt%5En%29%7D%20%3D%201-y%5C%5C%20%5C%5C%20-kt%5En%20%3D%20In%281-y%29%20%5C%5C%20%5C%5C%20k%20%3D%20%5Cdfrac%7B-In%281-y%29%7D%7Bt%5En%7D)
To calculate the value of k which is a dependent variable for the above equation ; we have:
![k = \dfrac{-In(1-0.40)}{200^{2.5}}](https://tex.z-dn.net/?f=k%20%3D%20%5Cdfrac%7B-In%281-0.40%29%7D%7B200%5E%7B2.5%7D%7D)
![k = 9.030 \times 10 ^{-7}](https://tex.z-dn.net/?f=k%20%3D%209.030%20%5Ctimes%2010%20%5E%7B-7%7D)
The time needed for 50% transformation can be determined as follows:
![y = 1-e ^{(-kt^n)} \\ \\ e^{(-kt^n)} = 1-y\\ \\ -kt^n = In(1-y) \\ \\ t =[ \dfrac{-In(1-y)}{k}]^{^{1/n}}](https://tex.z-dn.net/?f=y%20%3D%201-e%20%5E%7B%28-kt%5En%29%7D%20%5C%5C%20%5C%5C%20e%5E%7B%28-kt%5En%29%7D%20%3D%201-y%5C%5C%20%5C%5C%20-kt%5En%20%3D%20In%281-y%29%20%5C%5C%20%5C%5C%20t%20%3D%5B%20%5Cdfrac%7B-In%281-y%29%7D%7Bk%7D%5D%5E%7B%5E%7B1%2Fn%7D%7D)
![t_{0.5} =[ \dfrac{-In(1-0.4)}{9.030 \times 10^{-7}}]^{^{1/2.5}}](https://tex.z-dn.net/?f=t_%7B0.5%7D%20%3D%5B%20%5Cdfrac%7B-In%281-0.4%29%7D%7B9.030%20%5Ctimes%2010%5E%7B-7%7D%7D%5D%5E%7B%5E%7B1%2F2.5%7D%7D)
= 200.00183 min
The rate of reaction for Avrami equation is:
![rate = \dfrac{1}{t_{0.5}}](https://tex.z-dn.net/?f=rate%20%3D%20%5Cdfrac%7B1%7D%7Bt_%7B0.5%7D%7D)
![rate = \dfrac{1}{200.00183}](https://tex.z-dn.net/?f=rate%20%3D%20%5Cdfrac%7B1%7D%7B200.00183%7D)
rate = 0.00499 / min
rate of recrystallization = 4.99 × 10⁻³ min⁻¹
Answer:
43.89 min
Explanation:
Given that:-
The speed of light = ![3.00\times 10^8\ m/s](https://tex.z-dn.net/?f=3.00%5Ctimes%2010%5E8%5C%20m%2Fs)
The distance = ![7.9\times 10^8\ km](https://tex.z-dn.net/?f=7.9%5Ctimes%2010%5E8%5C%20km)
The conversion of distance in km to distance into m is shown below as:-
1 km = 1000 m
So,
Distance = ![7.9\times 10^8\times 1000\ m=7.9\times 10^{11}\ m](https://tex.z-dn.net/?f=7.9%5Ctimes%2010%5E8%5Ctimes%201000%5C%20m%3D7.9%5Ctimes%2010%5E%7B11%7D%5C%20m)
The relation between speed distance and time is shown below as:-
![Speed=\frac{Distance}{Time}](https://tex.z-dn.net/?f=Speed%3D%5Cfrac%7BDistance%7D%7BTime%7D)
Thus,
![3.00\times 10^8=\frac{7.9\times 10^{11}}{Time}](https://tex.z-dn.net/?f=3.00%5Ctimes%2010%5E8%3D%5Cfrac%7B7.9%5Ctimes%2010%5E%7B11%7D%7D%7BTime%7D)
![300000000\times time=10^{11}\times \:7.9\ s](https://tex.z-dn.net/?f=300000000%5Ctimes%20time%3D10%5E%7B11%7D%5Ctimes%20%5C%3A7.9%5C%20s)
Time = 2633.33 seconds
Also, 1 s = 1/60 min
So,
Time=![\frac{2633.33}{60}\ min=43.89\ min](https://tex.z-dn.net/?f=%5Cfrac%7B2633.33%7D%7B60%7D%5C%20min%3D43.89%5C%20min)