Answer:
Step-by-step explanation:
The model fo the shell is given by the following equation of equilibrium:

This first-order differential equation has separable variables, which are cleared herein:

The solution of this integral is:
![t = -\frac{m}{2b}\cdot \left[\tan^{-1} \left(\frac{v}{\sqrt{\frac{m\cdot g}{b} } }\right) - \tan^{-1} \left(\frac{600}{\sqrt{\frac{m\cdot g}{b} } }\right)\right]](https://tex.z-dn.net/?f=t%20%3D%20-%5Cfrac%7Bm%7D%7B2b%7D%5Ccdot%20%5Cleft%5B%5Ctan%5E%7B-1%7D%20%5Cleft%28%5Cfrac%7Bv%7D%7B%5Csqrt%7B%5Cfrac%7Bm%5Ccdot%20g%7D%7Bb%7D%20%7D%20%7D%5Cright%29%20-%20%5Ctan%5E%7B-1%7D%20%5Cleft%28%5Cfrac%7B600%7D%7B%5Csqrt%7B%5Cfrac%7Bm%5Ccdot%20g%7D%7Bb%7D%20%7D%20%7D%5Cright%29%5Cright%5D)

![\frac{v}{\sqrt{\frac{m\cdot g}{b} } }=\tan \left[-\frac{2\cdot b\cdot t}{m} + \tan^{-1}\left(\frac{600}{\sqrt{\frac{m\cdot g}{b} } } \right)\right]](https://tex.z-dn.net/?f=%5Cfrac%7Bv%7D%7B%5Csqrt%7B%5Cfrac%7Bm%5Ccdot%20g%7D%7Bb%7D%20%7D%20%7D%3D%5Ctan%20%5Cleft%5B-%5Cfrac%7B2%5Ccdot%20b%5Ccdot%20t%7D%7Bm%7D%20%2B%20%5Ctan%5E%7B-1%7D%5Cleft%28%5Cfrac%7B600%7D%7B%5Csqrt%7B%5Cfrac%7Bm%5Ccdot%20g%7D%7Bb%7D%20%7D%20%7D%20%20%5Cright%29%5Cright%5D)
![v = \sqrt{\frac{m\cdot g}{b} } \left [\frac{\tan \left(-\frac{2\cdot b \cdot t}{m} \right)+ \left(\frac{600}{\sqrt{\frac{m\cdot g}{b} } } \right)}{1 - \left(\frac{600}{\sqrt{\frac{m\cdot g}{b} } } \right)\cdot \tan \left(-\frac{2\cdot b \cdot t}{m} \right) }\right]](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7B%5Cfrac%7Bm%5Ccdot%20g%7D%7Bb%7D%20%7D%20%5Cleft%20%5B%5Cfrac%7B%5Ctan%20%5Cleft%28-%5Cfrac%7B2%5Ccdot%20b%20%5Ccdot%20t%7D%7Bm%7D%20%20%5Cright%29%2B%20%5Cleft%28%5Cfrac%7B600%7D%7B%5Csqrt%7B%5Cfrac%7Bm%5Ccdot%20g%7D%7Bb%7D%20%7D%20%7D%20%20%5Cright%29%7D%7B1%20-%20%5Cleft%28%5Cfrac%7B600%7D%7B%5Csqrt%7B%5Cfrac%7Bm%5Ccdot%20g%7D%7Bb%7D%20%7D%20%7D%20%20%5Cright%29%5Ccdot%20%5Ctan%20%5Cleft%28-%5Cfrac%7B2%5Ccdot%20b%20%5Ccdot%20t%7D%7Bm%7D%20%20%5Cright%29%20%7D%5Cright%5D)
Answer is C as all other choices are even numbers therefore make the equation non-integer.
So you make them the same common denominator
As you see, 2/10 = 8/40
2/4 = x/40, multiply by 10
2/4 = 20/40
Then add because same denominator
Now you would get:
8/40 + 20/40 = 28/40
Answer:
72-18=54
Step-by-step explanation:
Do good!
Answer:
18/6=3
Step-by-step explanation:
18/6÷3=6/2
6/2=3