Diffraction and communication

Starter Watch the video. Notice what happens to the waves after they hit the harbour wall. Can you explain this?

Learning Objectives Know a number of diffraction patterns. Know why different wavelengths are used for different communication purposes.

Success criteria Recall the wave patterns produced by a wave passing through different sized gaps. (Grade E - C) Explain why long wave radio waves have a very long range. Describe what the amount of diffraction depends on. (Grade B – A*)

Diffraction Diffraction is the spreading out of waves when they pass through a gap or around a large object.

Demo of diffraction with ripple tank

Copy and complete the following: Waves with a ________ wavelength show the most diffraction. Diffraction is greater when the gap is ________. Maximum diffraction occurs when...

Create a poster based on the last two lessons to show how information is sent using waves Last lessons success criteria This lessons success criteria Describe how information can be transmitted to satellites. (Grade C) Describe how different electromagnetic waves behave in the atmosphere. (Grade B) Explain why satellite dishes must be carefully aligned. (Grade A) Recall the wave patterns produced by a wave passing through different sized gaps. (Grade E - C) Explain why long wave radio waves have a very long range. Describe what the amount of diffraction depends on. (Grade B – A*)

Learning Objectives Know a number of diffraction patterns. Know why different wavelengths are used for different communication purposes.

Success criteria Recall the wave patterns produced by a wave passing through different sized gaps. (Grade E - C) Explain why long wave radio waves have a very long range. Describe what the amount of diffraction depends on. (Grade B – A*)

Plenary Sketch diagrams to show water waves of wavelength 3cm passing through gaps of: 8 cm 4 cm