Lesson 2 - Starter Question Which “colour” is created because a surface ABSORBS light?

Lesson 2 1.Define refraction. 2. Be able to draw diagrams of light refracting through objects.

Experiment Aim To study the refraction of light.

Sheet of Paper Method Glass block i Ray box with single slit Angle of Incidence 1.Draw around the glass block. 3. Draw in the normal. 4. Measure the angle of incidence, i. 5. Switch on the ray box. 2. Draw a straight line along which the ray of light will travel. Normal line

Sheet of Paper 6. Draw in the refracted ray as it leaves the glass block. 8. Measure the angle of refraction. 9. Repeat for different shapes of glass block. Method Glass block i Ray box with single slit Angle of Incidence Normal line 7. Switch off the ray box, remove the glass block and complete the path of the ray. r Angle of Refraction

Results – Rectangular Block i r This ray is parallel to the original incident ray. i o = yoyo r o = xoxo x y A ray parallel to the normal will pass straight through the block. Copy! i = angle of incidence r o = angle of refraction

Results – Triangular Block The ray bends towards the normal going into the block and away from the normal going out of the block. Copy!

Results – Semicircular Block The ray bends towards the normal going into the block. The ray will pass straight through the curved edge as it will strike parallel to the normal at that point. Copy!

Conclusion – Refraction Refraction is when light moves from one material to another (known as a medium) and changes speed. This is usually accompanied by a change in direction. Copy! Manipulating Light Video Clip

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N5 2014