Electromagnetic waves and matter | Middle school physics | Khan Academy

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Electromagnetic (light) waves travel along straight line paths. We can model these paths using rays. When a light ray encounters a boundary between different materials, the light can be reflected, absorbed, and/or transmitted. Most everyday objects don't emit their own visible light. We see these objects when visible light from a source reflects off of the object and into our eyes. Objects that absorb all colors of visible light appear black.

Sections:
00:00 - Intro
00:30 - EM waves and the ray model
01:38 - Reflection
02:43 - Absorption
04:06 - Transmission
06:19 - X-ray imaging
07:21 - Summary

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