Working with the boundary between two dielectrics. Attachments in Word.

In Figure A1 below the boundary between two ideal dielectrics is shown. Near the boundary, on Er1 side, the electric field is measured and found to be perpendicular to the boundary and equal to 100 Vm-1.

a) What is the direction of the electric field E, near that boundary?

b) What is the magnitude of E2?

Please see attachment below for the complete question.