2P07: Law of Reflection

It was a new term and it will be our first physics practical of the year. We will be experimenting with mirrors and light.

The experiment is as follows:

1. Place a plane mirror on a sheet of plain paper provided. Use a pencil to trace the outline of the plane mirror. Label the outline of the mirror as ABCD
2. Using a ray box, direct a ray of light at an angle, i = 20.0 degrees to P on the side AB of the plane mirror.
3. Use two crosses R and S to mark the ray incident on P and two more crosses T and U to mark the ray reflected from P.
4. Remove the plane mirror and the ray box. Draw a line OP normal to the plane. Draw a straight line through RS and TU. Let the line RS representing the incident ray meet the side AB at P. Let the line TU representing the reflected ray meet the side of AB also at P.
5. Use a protractor to measure the angles i and r and record in a table.
6. Repeat the experiment for different values of i.

From this experiment, I learnt about the law of reflection and how the angle of incident is always equal to the angle of reflection.