Force on a charge due to a square plate.

A particle having a charge q is fixed at a height h above the centre of a fixed square plate of uniform surface charge density $\sigma$ and side 2h .Find the electrostatic force on the charge due to square plate in N .

Details:

q=50 $\mu$ C

$\sigma$ =5 $\mu$ C/ $m^{2}$

h=10cm

Permittivity of free space= $8.85\times10^{-12}$ in S.I.

Hint: You do not need much of calculus ( i.e. not much integration involved).