Please!!! Help me.. I'm student. 1. The problem statement, all variables and given/known data 1. A light ray reflected from a flat mirror moves through an angle of 143* as the mirror is rotated. Through **what angle was the mirror rotated? 2. The speed of light in a material is 0,57c. what is the critical angle of a light ray at the interface between the material and a vacuum? 3.The electric field of plane electro magnetic wave is E=240V/m. At the same instant of time the magnetic field is....?