Physics - Diffraction of Waves Presentation

• There is an activity in IB Physics where students try to teach something.
• I will try to do that activity using Scrapbox Presentation Mode.
  • I can use LaTeX.

🌊 “Diffraction” of Waves

🔍 Examples

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📚 Prerequisite Knowledge

• Wave front

  • Blue line: "Wave front"

  • Red arrow: "Rays"

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Simulation

• https://www.compadre.org/osp/EJSS/4480/268.htm

🤔 Huygen’s Wave Theory

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• Proposes a new way to understand the movement of waves

• Suggests that every point on a wavefront is a source of waves

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  • These movements can be explained by the theory

Now, let’s move on to the more mathematical part. -

• Q. How does the wavelength $\lambda$and the opening of the obstacle $w$affect diffraction?

Q. How does the wavelength $\lambda$and the opening of the obstacle $w$affect diffraction?

• The diffraction effect is significant when $\frac{\lambda }{w}>1$
  • In other words, when the wavelength is comparable to or larger than the opening
• Generally, diffraction is larger when the wavelength is larger than the opening.

💪 Some questions Q. Why can we hear, but not see, the source behind a wall?

A.

• The wavelength of audible sound: 17mm - 17m
• The wavelength of visible light: 360nm - 400nm
• The wavelength of visible light is much smaller than the opening
  • —> Almost no diffraction of light Q.
• Hint: Use $c=f\lambda$

A.

Q. Draw the wavefronts of these waves as they emerge through the aperture.

• Waves of wavelength 1mm approaching an aperture of size 8mm
• Waves of wavelength 1mm approaching an aperture of size 1mm

A.