Answer:
Step-by-step explanation:
Force on electron in an electric field E = eE where E is electric field .
acceleration = eE / m where m is mass of electron .
Putting the values
4 x 10⁶ = 1.6 x 10⁻¹⁹ x E / 9.1 x 10⁻³¹
E = 22.75 x 10⁻⁶ N/C
The direction of electric field will be towards west ( opposite to east )
because of negative charge on electron .