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Reflection - IB Physics Definition

Reviewed by: Ann Howell

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In IB Physics, reflection occurs when a wave hits a boundary between two media and does not pass through, but instead bounces back to the original medium.

The law of reflection states that the angle of incidence, i, is equal to the angle of reflection, r.

Diagram showing light reflection, with incident and reflected rays, normal line, boundary, angle of incidence, and angle of reflection labelled.
Reflection of a wave at a boundary

When a wave is reflected, some of it may also be absorbed or transmitted through the medium. At a boundary between two media, the incident ray is the ray that travels towards the boundary. During reflection, the frequency, wavelength and speed of the wave does not change.

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Ann Howell

Reviewer: Ann Howell

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Ann obtained her Maths and Physics degree from the University of Bath before completing her PGCE in Science and Maths teaching. She spent ten years teaching Maths and Physics to wonderful students from all around the world whilst living in China, Ethiopia and Nepal. Now based in beautiful Devon she is thrilled to be creating awesome Physics resources to make Physics more accessible and understandable for all students, no matter their schooling or background.

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