Question

find the net force on the centre charge Q at the centre

Answer 1

Explanation:

4Q^2/l^2 ( where l is length of the each side of hexagon)only -Qand corner of -Q charge,+Q force exist other 4 eliminate each other

these is regular hexagon so all length are equal distance of -Q and middle +Qis (l/√2) ,also middle +Qand corner +Q charge same distance