Wave Patterns at the Spoke-Cleaning Basin

A Basin Test at the Bike Shop

At a community bike shop, Nia and Mateo tested a small paddle in a shallow basin of water. They wanted to model what happens when waves meet a floating foam marker. An adult kept the basin, paddle, and marker in the same places for each test. A resting level was marked on the side of the basin. Wave height was measured from the resting level up to a crest. Crest spacing was the distance from one crest to the next crest.

The students made four side-view model cards. Model P had crests 2 centimeters above the resting level. Neighboring crests were 10 centimeters apart. Model Q had crests 4 centimeters above the resting level, with neighboring crests 10 centimeters apart. Model R had crests 4 centimeters above the resting level, with neighboring crests 20 centimeters apart. Model S had crests 2 centimeters above the resting level, with neighboring crests 5 centimeters apart.

For each test, the paddle made a repeating pattern. The marker rose as a crest passed and fell as a lower part of the wave passed. The marker moved up and down, but it did not travel across the basin with a crest. The class recorded the marker's lowest-to-highest movement for each pattern.