Why does a pencil appear bent where it enters water? Trace a ray through a rectangular block and describe its change of direction at each boundary.

Pupils try “Trace a ray through a block”. Includes the editable PowerPoint, a 50-minute lesson plan and a printable pupil sheet with equipment, instructions, example evidence and worked teacher answers.

KS3 physics for ages 11–14. Part of the light, colour and vision sequence.

The Worksheets folder includes the glass-block ray-tracing investigation and a pupil thinking and review sheet.