Answer:
That is, mechanical waves cannot travel through a vacuum. This feature of mechanical waves is often demonstrated in a Physics class. A ringing bell is placed in a jar and air inside the jar is evacuated. Once air is removed from the jar, the sound of the ringing bell can no longer be heard.
False, all scene are combed for clues and photographed.
Answer:
The magnitude and algebraic sign of q is ![14\sqrt{2}\ \mu C](https://tex.z-dn.net/?f=14%5Csqrt%7B2%7D%5C%20%5Cmu%20C)
Explanation:
Given that,
Point charge = -0.70 μC[/tex]
We need to calculate the force for all charges
The electric force at first corner
![F_{1}=\dfrac{-k0.70\times10^{-6}q}{r^2}](https://tex.z-dn.net/?f=F_%7B1%7D%3D%5Cdfrac%7B-k0.70%5Ctimes10%5E%7B-6%7Dq%7D%7Br%5E2%7D)
The electric force at opposite corner
![F_{3}=\dfrac{-k0.70\times10^{-6}q}{r^2}](https://tex.z-dn.net/?f=F_%7B3%7D%3D%5Cdfrac%7B-k0.70%5Ctimes10%5E%7B-6%7Dq%7D%7Br%5E2%7D)
The net force is
![F=\sqrt{F_{1}^2+F_{2}^2}](https://tex.z-dn.net/?f=F%3D%5Csqrt%7BF_%7B1%7D%5E2%2BF_%7B2%7D%5E2%7D)
Put the value into the formula
![F=\sqrt{(\dfrac{-k0.70\times10^{-6}q}{r^2})^2+(\dfrac{-k0.70\times10^{-6}q}{r^2})^2}](https://tex.z-dn.net/?f=F%3D%5Csqrt%7B%28%5Cdfrac%7B-k0.70%5Ctimes10%5E%7B-6%7Dq%7D%7Br%5E2%7D%29%5E2%2B%28%5Cdfrac%7B-k0.70%5Ctimes10%5E%7B-6%7Dq%7D%7Br%5E2%7D%29%5E2%7D)
The electric force at second corner
![F_{2}=\dfrac{-kq^2}{2r^2}](https://tex.z-dn.net/?f=F_%7B2%7D%3D%5Cdfrac%7B-kq%5E2%7D%7B2r%5E2%7D)
The net force acting on either of the charges is zero.
So, ![F=F'](https://tex.z-dn.net/?f=F%3DF%27)
![\sqrt{(\dfrac{k0.70\times10^{-6}q}{r^2})^2+(\dfrac{-k0.70\times10^{-6}q}{r^2})^2}=\dfrac{kq^2}{2r^2}](https://tex.z-dn.net/?f=%5Csqrt%7B%28%5Cdfrac%7Bk0.70%5Ctimes10%5E%7B-6%7Dq%7D%7Br%5E2%7D%29%5E2%2B%28%5Cdfrac%7B-k0.70%5Ctimes10%5E%7B-6%7Dq%7D%7Br%5E2%7D%29%5E2%7D%3D%5Cdfrac%7Bkq%5E2%7D%7B2r%5E2%7D)
![\sqrt{2}\times\dfrac{0.70\times10^{-6}kq}{r^2}=\dfrac{kq^2}{2r^2}](https://tex.z-dn.net/?f=%5Csqrt%7B2%7D%5Ctimes%5Cdfrac%7B0.70%5Ctimes10%5E%7B-6%7Dkq%7D%7Br%5E2%7D%3D%5Cdfrac%7Bkq%5E2%7D%7B2r%5E2%7D)
![q=14\sqrt{2}\ \mu C](https://tex.z-dn.net/?f=q%3D14%5Csqrt%7B2%7D%5C%20%5Cmu%20C)
Hence, The magnitude and algebraic sign of q is ![14\sqrt{2}\ \mu C](https://tex.z-dn.net/?f=14%5Csqrt%7B2%7D%5C%20%5Cmu%20C)