A charged particle of mass m=2kg and charge 1 µC is projected from a horizontal ground at an angle $\mathrm{\theta }={45}^0$ with speed 10ms^-1  . In space, a horizontal electric field toward the direction of projection $\mathrm{E}=2\times {10}^7{\mathrm{NC}}^{-1}$ exists. The range of the projectile is