Testing the law of reflection: The angle of incidence = the angle of reflection.Aim. The aim of this experiment was to test the law of reflection: the angle of incidence equals the angle of reflection. This was done by projecting a ray of light at a flat mirror (ray of incidence) and measuring the angle made by the reflected ray (ray of reflection) and the normal. If the law of reflection is correct the angle between the normal and the ray of incidence and the angle between the normal and the ray of reflection should be the same.Hypothesis. It is predicted that the angle of incidence will equal the angle of reflection no matter what angle we change the ray of incidence to hit the mir ...view middle of the document...
We labelled the ray of incidence, which is the original ray of light aimed at the mirror and we labelled the ray of reflection, which is the ray reflected off the mirror. Using these two rays and the normal we could label the angle of incidence (the angle between the normal and the ray of incidence) and the angle of reflection (the angle between the normal and the ray of reflection). Once the two angles had been labelled we could use a protractor and measure them. We lined the base of the protractor up with the normal and measured the angle that was created by the two different rays. We then recorded this on the diagram. Once the diagram had been completely labelled and measured we named the diagram Ray 1.We repeated this process 3 more times but carefully directing the ray of light at different angles towards the mirror. Some acute and some obtuse, this was so we had a variety of angles to measure. We continued to label the diagrams and name them appropriately: Ray 2, Ray 3 etc.When we had finished all 4 diagrams and they were correctly labelled we had to create a new diagram, but this one was different to the others. The ray of light from the light box had to be positioned at a 900 angle to the mirror. We called this diagram ray 5 and we labelled it just like we had labelled the previous diagrams with the normal and the different rays, angles etc. After the normal procedure we recorded any observations about ray 5 that were different to the other rays or about anything we noticed.There were three of us in the group who conducted this experiment and each of us took a turn to record our own copy of the different rays on our own sheet of paper.When we were completely finished drawing the diagrams, labelling them and writing about them we packed up our equipment. Then we recorded our results in a table, the results show the angle of incidence and the angel of reflection for all five rays. This table is called Table 1 and is seen below.
Rays
Angle of incidence
Angle of reflection
Ray 1
390
390
Ray 2
570
550
Ray 3
230
230
Ray 4
700
720
Ray 5
00
00
Table 1: Angle of incidence compared to the angle of reflection.Discussion.My results do support the law of reflection to a point. Ray 1, Ray 3 and Ray 5 both support the law of reflection because in all of them the angle of incidence and the angle of reflection are equal. Ray 1's angles are 390 , Ray 3's angles are 230 and Ray 5 doesn't have any angles because of the angle that it was directed to the mirror at therefore it is 00. But then there is Ray 2 and Ray 4. Ray 2's angles are 700 and 720 , there is only a difference of 20 between the two angles. The same goes for Ray 2 with angles of ...
