IB Physics – Reflection & Refraction Lab
Part 1: Reflection
Goal: Determine the relationship between the incident light and reflected light off of a
plane (flat) mirror.
Procedure: Design a method that will allow you to measure the incident and reflected
angles of light on a plane mirror for various angles. Make sure that you do not look
directly at the laser – it will burn your eyes!
Table I
Plane Mirror
θi
θr
Analysis: Make a half page graph of θr and θi. Determine the equation of the trend.
Part 2: Refraction
Goal: Determine the mathematical description for the refraction of light as it passes
from one medium to another.
Procedure: Choose a refractive medium (either a hollow plastic container filled with
water or a solid plastic semi-circle). Use the double-pin-sighting method to gather
data to complete the data table.
Table II
Refractive medium:
________________
θi
θr
0
10
20
30
40
45
50
55
60
65
70
75
Analysis: Make a half page graph of θr and θi. Make a second half page graph of
sin(θr) and sin(θi). Determine the equation of each curve.
Questions:
1. What is the general mathematical description for the refraction of light?
2. Why is the semi-circular shape necessary? What would happen if the object had
parallel sides? Use drawings to explain.
3. What is the index of refraction for the material? Be careful with this calculation!
4. What is the difference between refraction and reflection? Use a diagram to support
your explanation.
5. Explain, including a diagram, how optical fibers transmit light signals long
distances without appreciable loss of light intensity. In your explanation, include a
discussion of critical angle, total internal reflection, optical density, incident angle and
refracted angle.