We have to calculate the electric field in the center, so we need the distance to the center R and the interaction of each charge with that point
![E=\sum_{n\mathop{=}0}^(\infty)E_i](https://img.qammunity.org/2023/formulas/physics/college/nu949yisjppp1i4hf4cmevho24db4l0r1x.png)
To calculate the distance R we have a triangle
![R=\sqrt{(2a^2)/(4)}=(a)/(√(2))=0.014m=1.41cm](https://img.qammunity.org/2023/formulas/physics/college/g5n1y6ns2zqj1g9w6cvhfontxguyw229dv.png)
![\begin{gathered} \sum_{n\mathop{=}0}^(\infty)Ex=(9\cdot10^9)/(2\cdot10^(-4))\cdot(cos45)\cdot(6C)=1.91\cdot10^(14)N/C \\ \sum_{n\mathop{=}0}^(\infty)Ey=4.5\cdot10^(13)\cdot(cos45\degree)(2C)=0.636\cdot10^(14)N/C \\ Etot=√(Ex^2+Ey^2)=2.01\cdot10^(14)N/C \end{gathered}](https://img.qammunity.org/2023/formulas/physics/college/lfqwlv4go6w32z0kdb7gupdi99bxqb0h02.png)
Is important to remember that E has direction so you have to calculate each axis, x, and y