FISIKA Kelas 11 - Gelombang Cahaya | GIA Academy

Introduction

This tutorial covers the essential concepts of light waves as outlined in the FISIKA Kelas 11 video by GIA Academy. It focuses on key properties of light, including reflection, refraction, interference, diffraction, dispersion, and polarization. Understanding these concepts is crucial for mastering physics at this level and can help in practical applications such as optics and wave behavior.

Step 1: Understanding Reflection

• Definition: Reflection occurs when light bounces off a surface.
• Law of Reflection: The angle of incidence equals the angle of reflection.
• Practical Applications:
  • Mirrors utilize reflection to produce clear images.
  • Understanding reflection is essential in designing optical instruments.

Practical Tips:

• Experiment with different surfaces (like smooth vs. rough) to see how they affect reflection.

Step 2: Exploring Refraction

• Definition: Refraction is the bending of light as it passes from one medium to another.
• Snell’s Law:
  • Formula: n1 * sin(θ1) = n2 * sin(θ2)
  • Where n1 and n2 are the refractive indices of the two media, and θ1 and θ2 are the angles of incidence and refraction.
• Practical Applications:
  • Lenses in glasses and cameras use refraction to focus light.

Common Pitfalls:

• Be cautious with angles; ensure you measure from the normal (perpendicular) line at the boundary of two media.

Step 3: Learning About Interference

• Definition: Interference occurs when two or more light waves overlap and combine.
• Types:
  • Constructive interference: waves add up to make a larger amplitude.
  • Destructive interference: waves cancel each other out.
• Applications:
  • Used in technologies like noise-cancelling headphones and optical coatings.

Experimentation:

• Try setting up a double-slit experiment to visually observe interference patterns.

Step 4: Investigating Diffraction

• Definition: Diffraction is the bending of light waves around obstacles or through openings.
• Key Concept: The amount of diffraction increases with longer wavelengths.
• Applications:
  • Diffraction gratings can separate light into its component colors.

Practical Tips:

• Use a CD or DVD as a simple diffraction grating to see how light disperses.

Step 5: Understanding Dispersion

• Definition: Dispersion occurs when light separates into its component colors as it passes through a medium.
• Example: A prism disperses white light into a spectrum of colors.
• Applications:
  • Used in spectroscopy to analyze materials.

Experimentation:

• Shine white light through a prism to observe the dispersion of colors.

Step 6: Learning About Polarization

• Definition: Polarization refers to the orientation of light waves in a particular direction.
• Types:
  • Linear polarization: light waves oscillate in one direction.
  • Circular polarization: light waves rotate in a circular motion.
• Applications:
  • Polarizing filters in photography reduce glare and enhance contrast.

Common Pitfalls:

• Ensure the polarizing filter is aligned correctly to achieve the desired effect.

Conclusion

This tutorial outlined the fundamental properties of light: reflection, refraction, interference, diffraction, dispersion, and polarization. Mastering these concepts is essential for further studies in physics and practical applications in technology and everyday life. To deepen your understanding, consider conducting experiments or exploring advanced topics related to each property.