PRACTICAL - investigating light

what is the method for using transparent materials to investigate refraction?

1. trace a transparent block on paper

2. use a ray box to shine a ray of light at the middle of one side of the block

3. remove block

4. join the incident ray and emerging point to show the path of the refracted ray through the block

5. draw the normal at the point where the light ray entered the block

6. measure the angle of incidence and the angle of refraction

   • with protractor

7. repeat the experiment with blocks of different materials, keeping the incident angle the same

what does the investigation using transparent materials show?

• refraction changes for different materials

  • due to different optical densities

what is the method showing different materials reflecting light by different amounts?

1. draw a straight line on a piece of paper

2. place an object so one of the sides line up with the line

3. shine a ray of light at the object’s surface

4. trace the incoming and reflected light beams

5. draw the normal where the ray hits the object

6. measure the angle of incidence and refraction

7. repeat the experiment for various objects

what materials can you use to show different materials reflecting light by different amounts?

• smooth surfaces

  • can see how they give clear reflections

• rough surfaces

  • diffuse reflection

• finds the angle of incidence = angle of reflection