A mirror does something wonderfully predictable: whatever angle a ray of light arrives at, it leaves at the very same angle on the other side of an imaginary line. Master that line, the normal, and ray diagrams stop being guesswork.
The law of reflection states that the angle of incidence equals the angle of reflection, both measured from the normal. The image in a plane mirror is virtual, upright, the same size as the object, laterally inverted, and as far behind the mirror as the object is in front.
The law of reflection states that the angle of incidence equals the angle of reflection, both measured from the normal.
The normal is the line drawn at right angles to the mirror at the point where the ray hits.
Change the angle of the incoming ray and watch the reflected ray and the angles from the normal.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
The law of reflection states that the angle of incidence...
Angles in reflection are measured from...
The image in a plane mirror is...
The image in a plane mirror is as far behind the mirror as...
The law fixes the angles; the image in a plane mirror always has the same set of properties.
Always measure the angles from the normal, the line perpendicular to the mirror, not from the mirror surface. Measuring from the surface is the single most common reason ray diagrams lose marks.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
A ray strikes a plane mirror at 30 degrees to the normal. The angle of reflection is...
A ray travels along the normal and strikes a plane mirror (angle of incidence 0 degrees). It reflects...
In a plane mirror, the image of the letter b appears as...
Reflection mastered. The light strand continues with refraction.