Three charges \(+20\,\mu C\), \(+20\,\mu C\) and \(-20\,\mu C\) are placed at the vertices \(A\), \(B\) and \(C\) respectively of an equilateral triangle of side \(1\,m\). Find the net force acting on the charge at vertex \(A\).
Show Hint
Always solve Coulomb force problems in two steps:
\[
\boxed{\text{Step 1: Calculate each force using Coulomb's law}}
\]
\[
\boxed{\text{Step 2: Add the forces vectorially}}
\]
In an equilateral triangle, remember that the angle between two sides is
\[
\boxed{60^\circ.}
\]
Each $+20\,\mu$C charge exerts an equal attractive Coulomb force on the $-20\,\mu$C charge. By the symmetry of the equilateral triangle, the components perpendicular to the axis of symmetry cancel, and the resultant force points from the $-20\,\mu$C vertex toward the midpoint of the opposite side.