### This shows how water waves react as they pass through depth changes.

**WATCH THE VIDEO**

**Teachable Topics:**

- Refraction
- Snell's Law
- Wavelength and Frequency

**Theory:**

Refraction is the bending of waves as they travel from one medium into another. The amount the waves bend by depends on the angle of the incident waves and the speed of the waves in the two mediums.

For waves moving from one medium (medium 1) into another (medium 2), the angle of refraction can be found through the ratio:

sin (θ_{1}) / sin (θ_{2}) = v_{1} / v_{2}

where θ_{1 }is the angle of incidence, θ_{2} is the angle of refraction, v_{1 }is the velocity of the waves in the first medium, and v_{2 }is the velocity of the waves in the second medium.

**Apparatus:**

- Ripple Tank

**Procedure:**

- Set up the ripple tank and turn it on.
- Change the depth of the water the waves move through by placing pieces of clear plastic underneath the water. Observe how the waves bend through these areas of different depth.