Experiment
Light box or laser, Semicircular plastic or glass prism, Circular protractor, pasco optical kit or hardtl disk
first, we use light strike at the flat surface of the semicircular plastic, and then we change the angle every t 10 degree every time we move the light until 70 degree to get the incidence angle and the refracton angle, and calculate sine value of them.
the data we revived from the first set of data is when light is on the flat side of the lens, we can see that the change of the angle that we measured is changing linearly to the sin(incidence) and sin(refraction). when we try to go pass 80 % the sin(incidence) and sin(refraction) become undef, this happens if the light is trapped in the lens.
the graph is to show the change of the reflection angle, and the change of the refraction angle.
for the second part of the experiment, we view the light going in through the curved side of the lens, which effects the angle of refraction not quite linearly any more, it is more like its going 1/x^2, but the light does gets trapped inside the lens, a lot faster then when the light is going through the straight side first.
The light ray may become dimmer when it enter curved surface of the semicircular prism as there is some amount of light ray reflected at the curved surface. The light ray travels from lower density to higher density from air to plastic and higher density to lower density from plastic to air.
we were not able to complete all 10 trials, the angle of refraction got too small for us to take data with visible light.
analysis
form this experiment we can see that the effect of reflection and refraction on the light through a different medium at an angle.partI of the lab showed that the relationship of the reflection and refraction was linear,due to the flat surface of the lens, partII of the lab focused on the curved side, and the refraction angle changed proportion to the reflection angle by 1/x^2. no light escapes from the lens after about 40 degrees change in the incidence angel.
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