Start with water waves
Teaching Guidance
for 14-16
Water waves and ripple tanks

There is a long tradition of starting with water waves when teaching about waves and radiation in physics. This makes a lot of sense because, unlike with light and sound, it is possible actually to see the water waves being reflected, refracted, diffracted and interfering.
In addition, the first hand nature
of water waves is a good starting point for explaining interference effects with:
- Constructive interference leading to the creation of double-sized water waves
- Destructive interference leading to
flat water
It would be worth checking to see whether your school has a ripple tank that can be used to demonstrate all of these effects.
Teacher Tip: You'll need to practice, and to pay particular attention to the setting up instructions – getting the depth of the water correct is often crucial.