3h sáng còn ai thức ko nhỉ :)
\(E_{AO}=\frac{k\left|q\right|}{AO^2}=E_{BO}=E_{CO}=E_{DO}\)
\(AO=BO=CO=DO=\sqrt{\frac{a^2}{2}}=\frac{a\sqrt{2}}{2}\)
\(\Rightarrow E_{AO}+E_{CO}=\frac{2k\left|q\right|}{\frac{a^2}{2}}=\frac{4k\left|q\right|}{a^2}\left(V/m\right)\)
\(E_{BO}+E_{DO}=\frac{2k\left|q\right|}{BO^2}=\frac{2k\left|q\right|}{\frac{a^2}{2}}=\frac{4k\left|q\right|}{a^2}\left(V/m\right)\)
\(\Rightarrow\sum E=\sqrt{\left(E_{AO}+E_{CO}\right)^2+\left(E_{BO}+E_{DO}\right)^2}=\sqrt{\frac{16k^2q^2}{a^4}+\frac{16k^2q^2}{a^4}}=\sqrt{\frac{2.16.k^2q^2}{a^4}}=\frac{4k\left|q\right|}{a^2}\sqrt{2}\left(V/m\right)\)
Ok con dê, ko hiểu chỗ nào hỏi liền nhé :)
@Hoàng Tử Hà Kìa bro :vvvv