Electrostatics Part 2

An electron is moving under the influence of the electric field of a uniformly charged infinite plane sheet S having surface charge density +σ. The electron at t=0 is at a distance of 1m from S and has a speed of 1m∕ s. The maximum value of σ if the electron strikes S at t=1 s is α[‌

m∈0

e

]‌

C

m2

the value of α is___