GEOMETRICAL OPTICS
Materials
Miniature light bulb Power supply
Holder for Light Bulb Meter Stick
Laser Face Powder
Transparent Ruler Small Paper Disk
Graph Paper Glass Rod
Semicircular transparent chamber filled with a slightly cloudy liquid Pencil
Clear Plastic ruler Protractor
Graphing paper Flashlight
Prism Solid Clear Cylinder
Holder for Light Bulb Meter Stick
Laser Face Powder
Transparent Ruler Small Paper Disk
Graph Paper Glass Rod
Semicircular transparent chamber filled with a slightly cloudy liquid Pencil
Clear Plastic ruler Protractor
Graphing paper Flashlight
Prism Solid Clear Cylinder
Results
Activity No. 1
"A Thousand Points of Light" - Light from the bulb traveled in different directions whereas the light from the laser pointer traveled in a single direction only.
Activity No. 2
"Understanding Light Rays" - When an incident light ray hits on the surface of an object, it produces a small angle as the light ray refracts.
Activity No. 3
"Laws of Reflection and Refraction" - The relationship between the angle of incidence and the angle of reflection is proportional.
Activity No. 4
"Dispersion and the Rainbow" - When a red laser light was incident in the prism, it just showed a red light. But when white light is incident in the prism, the light disperses and eventually we can see a "Rainbow".
"A Thousand Points of Light" - Light from the bulb traveled in different directions whereas the light from the laser pointer traveled in a single direction only.
Activity No. 2
"Understanding Light Rays" - When an incident light ray hits on the surface of an object, it produces a small angle as the light ray refracts.
Activity No. 3
"Laws of Reflection and Refraction" - The relationship between the angle of incidence and the angle of reflection is proportional.
Activity No. 4
"Dispersion and the Rainbow" - When a red laser light was incident in the prism, it just showed a red light. But when white light is incident in the prism, the light disperses and eventually we can see a "Rainbow".
Discussion
In the Activity No. 1, it is observed that the light from the bulb travels in different directions since it does not follow a single path of light unlike that of a laser pointer. So as we can see, light from the laser pointer travels in just one direction. By the use of face powder, you can see the path of light a laser pointer travels. In the second activity: When a light ray travels from one medium to another, part of the incident light is reflected and part of the light is transmitted at the boundary between the two media. The transmitted part is said to be refracted in the second medium. For the 3rd Activity: In general, when light enters a new material its direction will change. The angle of refraction θ2 is related to the angle of incidence θ1. Snell’s Law be written as: n1sinθ1 = n2sinθ2
For the last activity:
For the last activity:
- Dispersion occurs whenever there is a process that changes the direction of light in a manner that depends on wavelength. Dispersion can occur for any type of wave and always involves wavelength-dependent processes.
- For a given medium, n increases as wavelength decreases and is greatest for violet light. Thus violet light is bent more than red light, as can be seen with a prism.
- In a rainbow, light enters a drop of water and is reflected from the back of the drop. The light is refracted both as it enters and as it leaves the drop.
Conclusion
Light is everywhere in our world. We need it to see: it carries information from the world to our eyes and brains. Seeing colors and shapes is second nature to us, yet light is a perplexing phenomenon when we study it more closely.
Sources
https://www.boundless.com/physics/textbooks/boundless-physics-textbook/geometric-optics-24/reflection-refraction-and-dispersion-169/dispersion-rainbows-and-prisims-611-6326/
http://web.pdx.edu/~bseipel/lecture%20notes%207-%20203%20optics.pdf
http://web.pdx.edu/~bseipel/lecture%20notes%207-%20203%20optics.pdf