# Reflection and Refraction in Waves

• Created by: Julia V
• Created on: 27-06-18 19:03
• Reflection and Refraction
• Reflection
• Angle of Incidence = Angle of Reflection
• Angle of Incidence = the angle between the INCOMING WAVE and the NORMAL
• Angle of Reflection = the angle between the REFLECTED WAVE and the NORMAL
• The NORMAL
• An imaginary line that's PERPENDICULAR at the surface of the POINT OF INCIDENCE (surface where wave hits the boundary)
• Usually shown as a dotted line
• Specular Reflection
• When a wave is reflected in a single direction by a smooth surface
• E.g when LIGHT is reflected by a MIRROR = CLEAR reflection
• Diffuse Reflection
• When a wave is reflected by a rough surface and the reflected waves are are SCATTERED in LOTS OF DIFFERENT DIRECTIONS
• Refraction
• When light waves are bent when they enter an new MEDIA (material)
• If a wave crosses a boundary and SLOWS DOWN it will bend TOWARDS THE NORMAL.
• If a wave crosses the boundary and SPEEDS UP it will bend AWAY from the normal.
• The wavelength changes but the frequency stays the same
• The Optical density of a material is a measure OF HOW QUICKLY LIGHT can travel through it. The HIGHER the optical density, the SLOWER the light waves travel through it.