OUTCOME
By the end of the lesson you will be able to identify the properties of a wave and recognise sound as a longitudinal wave of variations in pressure.
Mechanical waves can travel as transverse or longitudinal waves. Sound is a longitudinal wave and can be represented graphically as a pressure wave.
LEARNING TASKS
Explore
Use the slinky to model a transverse and then a longitudinal wave.
Complete the slinky experiment
Elaborate
After watching the video
1. How are sound created?
2. How does sound differ when it travels through solids, liquids or gasses?
3. What is the wavelength in a sound wave?
4. What is a rarefaction?
5. What is the number of wavelengths in a second called?
6. What happens when sound hits a solid surface?
7. How can sound be used to determine depth?
Evaluate
Answer Qs 1 & 2 from the text.
Your baby ultrasound. Your parents probably have a video of this, possibly even on CD. If you can find it bring it in, if you have any stills, bring them in.
HW: pre-reading and summaries for next lesson