Year 11 were set a homework question today on the loud hailer. This is from a previous GCSE exam.

In order to answer the first part of question correctly, students need to recall the wave speed equation which is:

 WAVE SPEED = FREQUENCY  x WAVELENGTH

The equation needs to be rearranged to work out the wavelength

so WAVELENGTH = WAVE SPEED / FREQUENCY

The rest of the question requires students to think about the application of diffraction (spreading of waves) that they have learned about in class today. Think about the size of the loud hailer and the size of the waves, and the effect that this will have on their spreading (and reaching an audience).

Students who may have mislaid their sheet can download another here

Complete the sheet 7Fa/3 (reaction or no reaction ?)

If you have mislaid your sheet, you can download another one here

This work needs to be handed in no later than thursday 1st March

Diffraction is a very unusual effect. It is the spreading of waves. You must remember that in order for diffraction to happen, the gap in the obstacle must be the same size as the wavelength of the wave, otherwise the effect is much weaker.

If you like watching TV, you shouldn’t buy a house at the bottom of a hill, unless you want to pay to have SKY. Why is this?

Notes, diagrams and questions about this topic can be downloaded here