The moons of the planet Neptune move in circular paths around the planet. They continuously accelerate towards the centre of Neptune. The acceleration changes the of each moon but does not change its The force causing the acceleration is a force. Reflection and Refraction L.O.: What can say about the reflection of a light ray by a plane mirror? What is refraction? previous HW: and worksheets) Tomorrow: bring a ruler Reflection Reflection Reflection Reflection ACTUAL light path APPARENT light path OBJECTIMAGE: same size, equal distance behind normal 1. PLANE (FLAT) MIRROR VIEWER Law of Reflection: equal angles 6-Feb-16 Location of image The image formed by a plane (flat) mirror is: the same distance behind the mirror as the object is in front of it. PLANE MIRROR: UPRIGHT, SAME SIZE, VIRTUAL The image seen in a mirror is a virtual image. The light rays appear to come from the image. A virtual image cannot be projected onto a screen. Real images: Can be projected onto screens. They are produced by focusing light rays onto a screen. Refraction What happens when light crosses an interface ( a boundary between two transparent media) ? Refraction Refraction Refraction Refraction But, if light meets a boundary between two transparent materials at an angle of 90 o (i.e along the normal) then, there is NO change in direction. Workbook page 110, questions: 1a-b & 3. Starter: When a wave crosses the boundary between one medium and another the wave _____- changes. If light travels across the boundary into a ___ dense material, the light slows down and the wavelength decreases. The ______ doesnt change. If light strikes the surface along the _____, it will not change directions. Clues: Frequency: it depends on the source Speed: depends on the medium Starter: When a wave crosses the boundary between one medium and another the wave _____- changes. If light travels across the boundary into a ____ dense material, the light slows down and the wavelength decreases. The ___________doesnt change. If light strikes the surface along the ________, it will not change directions. Clues: Frequency: it depends on the source Speed: depends on the medium speed more frequency normal