This investigation into the 5 main properties of all waves (Reflection, Refraction, Diffraction, Interference, Doppler Effect) can be used in several different ways:

1. Introduce the Concepts for the 1st time

2. Distance Learning/Self-Guided Learning

3. Follow-up to your own lesson

4. Group/Partner cooperative learning

I use this as a walk-through of the concepts after a discrepant event to start the concept off.

(Disappearing Penny - With class gathered around, simply drop a penny on the table, then put a large beaker or glass on top of penny. Pour water in the beaker/glass and so long as they are watching from the sides of the cup, the penny will gradually disappear)

After this, their job is to work with a partner to go through each of the 5 properties and learn enough about them to decide which one is responsible for the penny "disappearing."

What's nice about doing this investigation before teaching it, is that I can constantly refer back to each of the properties they saw firsthand in my own, more direct instruction and they have something to visualize to help them out.

They'll use a free online ripple tank simulator to investigate these properties. This thing can simulate pretty much every wave related phenomenon in the galaxy, but its also perfect for these simple properties. It allows them to play around with the waves and see it in multiple speeds and from multiple angles.

That being said, it'll obviously require a laptop or computer of some sort.