Investigating refraction

Question 1

What is the apparatus for investigating how the nature of how light waves change direction when they move from air into glass?

Answer 1

Ray box and slits, 12V power supply, glass block, protractor, A3 paper, sharp pencil.

Question 2

What is the method for investigating the nature of how light waves change direction when they move from air into glass?

Answer 2

1) Place the rectangular block on the A3 paper and draw around it with the sharp pencil.
2) Draw the normal line, which will be at right angles to the side of the block towards which the light ray will be shone.
3) Using the protractor and pencil, mark on the paper angles of incidence of 0 degrees through to 80 degrees in 10 degree intervals.
4) Starting with 0 degree angles (the light ray travelling along the normal line), direct the light ray towards the block and mark its exit point from the block with a sharp pencil dot.
5) Remove the glass block and join the dot to the point of incidence by drawing a straight line. Measure and record this angle, which is the angle of reflection.
6) Repeat for all of the other angles from 10 to 80 degrees.

Question 3

What is the conclusion achieved when investigating the nature of how light waves change direction when they move from air into glass.

Answer 3

When a light ray travels from air into a glass block, its direction changes and the angle of refraction will be less than the angle of incidence unless it is travelling along the normal.