Name: XXXXXXXXXXSection Date
Ferdinand S. Bautista, Manila Science High School
REFRACTION OF LIGHT
OBJECTIVE: 1. Describe how light bends when it travels from one medium to another.
2. Measure the index of refraction of different materials
MATERIALS Bending Light XXXXXXXXXXPhET simulation, spreadsheet
ONLINE
RESOURCES
Bending Light XXXXXXXXXXPhET simulation : https:
phet.colorado.edu/sims/html
ending-
light/latest
ending-light_en.html
PROCEDURE
Refraction 1. Open the Bending Light PhET simulation and select the “More Tools” tab.
2. Set the following parameters:
Medium 1 Air
Medium 2 Water
Laser View Ray
Wavelength 650 nm
Normal Line Enabled
Angles Enabled
3. Turn on the laser source.
4. Using the protractor in the “Toolbox” measure the angle of incidence, I, (the angle
etween the normal line and the ray of light from the source), the angle of reflection,
(The angle between the normal line and the reflected ray), and the angle of refraction,
, (the angle between the normal line and the transmitted ray).
Angle of
Incidence
Angle of
Reflection
Angle of
Refraction
Air to Water
Water to Ai
5. Using the Speed Meter in the Toolbox, measure the speed of the incident ray,
eflected ray, and refracted ray.
Speed of
Incident Ray
Speed of
Reflected Ray
Speed of
Refracted Ray
Air to Water
Water to Air
6. Repeat procedures (3) – (5), but this time, select “Water” as the first medium and
“Air” as the second medium.
Guide Questions:
https:
phet.colorado.edu/sims/html
ending-light/latest
ending-light_en.html
https:
phet.colorado.edu/sims/html
ending-light/latest
ending-light_en.html
Name: XXXXXXXXXXSection Date
Ferdinand S. Bautista, Manila Science High School
1. What happens to the light from the laser when it strikes the boundary between air
and water?
2. What relationship exists between the angle of incidence and the angle of reflection?
3. How does light bend when it travels from air to water? water to air?
4. What happens to the speed of light when it travels from air to water? water to air?
Index of Refraction
and Angle of
Refraction
1. Set the following parameters:
Medium 1 Air
Medium 2 Water
Laser View Ray
Wavelength 650 nm
Normal Line Enabled
Angles Enabled
2. Turn on the laser and using the protractor measure the angle of incidence and the
angle of refraction.
3. Increase the angle of incidence by moving the laser away from the normal. Observe
what happens to the angle of refraction as the angle of incidence increases.
4. Using the protractor, measure the angle of refraction at different angles of incidence,
3° < ? ≤ 40. Repeat the procedure for light travelling from air to glass.
Direction of
Propagation of
Light
Angle of
Incidence, i
(degrees)
Angle of
Refraction,
(degrees)
sin i sin r
Air to Wate
Air to Glass
5. Using a spreadsheet, plot the values of sin i (along the y-axis) against the values of
sin r (along the x-axis) for each case. Describe the shape of each graph.
6. Calculate the slope of each graph and compare these slopes to the refractive index of
water and refractive index of glass.
Guide Questions:
• What happens to the angle of refraction as the angle of incidence increases?
Name: XXXXXXXXXXSection Date
Ferdinand S. Bautista, Manila Science High School
• What do the graphs of sin i against sin r suggest about the relationship between sin i
and sin r? Express the relationship as a mathematical expression.
• How does the index of refraction of water compare with the slope of the graph for
light travelling from air to water?
• In which material, water or glass, does light bend more? How does the amount of
ending depend on the indices of refraction of the two media (air-to-water, air-to-
glass)?
CONCLUSION(S)
GOING
FURTHER
1. Determine, experimentally, the indices of refraction of Material A and Material B. Which
has a higher index of refraction?
2. Does the refractive index of a certain material depend on the color of light incident on it?
Using the simulation, design an experiment to investigate the dependence of the material’s
efractive index on the color of light incident on it.