A particle having charge that of an electron and mass 1.6×10−30kg is projected with an initial speed u at an angle 45∘ to the horizontal from the lower plate of a parallel plate capacitor as shown in the figure. The plates are sufficiently long and have separation 2cm. The maximum value of velocity of particle not to hit the upper plate is W×106m s−1. Take electric field between the plates as 103V m−1 directed upward. Find W.