OUTCOME
By the end of the lesson you will recognise the difference between sound level and sound intensity and be able to use the relationships to calculate both measures.
Intensity is a measure of how much accoustic power is distributed over an area. Intensity is correlated to loudness, which is how we experience changes in intensity. The decibel is a logarithmic measure of the ratio of intensity compared to the human threshold of hearing
LEARNING TASKS
Explain
Explain why loudness and intensity are not always directly related
Why is does the decibel use a logarithmic scale?
Explore and Elaborate
Prac: Inverse square law
Down load a decibel meter
or
Use you decibel meter to test sounds around the school
Evaluate
Make sure you have answered all of the questions from the practical activity
Revision Qs 23.8, 23.11
Qs 17-25 Reading for next class p.20-23