A light beam travelling in the x−direction is described by the electric field: Ey = 270 sin ω(t – x/c). An electron is constrained to move along the y−direction with speed of 2 × 10⁷ m/s. The maximum electric force on the electron is

4.32 × 10^-17 N

$E=E_0 \sin \omega(t-x / c)$

$E_0$ = 270 V/m

$B_0=\frac{E_0}{c}=9 \times 10^{-7}$ T

$F_e=q E_0=1.6 \times 10^{-19} \times 270=4.32 \times 10^{-17}$ N