Four equal charges `2.0xx10^(-6) C` each are fixed at the four corners of a square of side 5 cm. Find the coulomb force experienced by one of the charges due to the rest three.

Explanation

`q=2xx10^-6C, a=5cm=0.05m `
` vecF_(BA)=(9xx10^9xx(2xx10^-6)^2)/(0.05)^2 `
` =(9xx10^9xx4xx10^-12)/(25xx10^-4) = 14.4N `
` vecF_(CA)=(9xx10^9xx(2xx10^-6)^2)/(sqrt(2)xx0.05)^2 `
` =(9xx10^9xx4xx10^-12)/(25xx2xx10^-4)=7.2N `
` vecF_(DA)=vecF_(BA) `
`Resultant force at A = vecF_(BA)+vecF_(CA)+vecF_(DA) `
` =14.4veci+[7.2(veci)/(sqrt2)+7.2(vecj)/(sqrt2)]+14.4vecj `
` =27.5N at 45^@ `
with the extended sides of the square from the charge considered.