Rays, boundaries and the normal
Rays, boundaries and the normal
A ray shows the direction that light energy travels. At a boundary between two materials, draw a normal at right angles to the surface and measure every angle from that normal.
Step-by-step lessons on Edexcel A Level Physics Refraction and total internal reflection. Each one builds up to exam-style questions. Physics is one of the most mathematically demanding A Levels -- at least 40% of the marks across the three papers require maths skills at Level 2 (GCSE) standard or above, so build calculation and graph-handling fluency alongside the conceptual content from the start.