4. Try producing surface and internal
waves using the wave paddle.
For surface waves, lower the
paddle into the water and raise it
again, repeating the cycle at a fast
frequency (at least once a second).
For internal waves, do this more
slowly (about once every 10 seconds).
5. Discuss your results.
6. Optional: if you have time, you
can repeat the experiments using
the piece of plastic inserted at an
angle to the bottom of the tank,
to give the effect of a shallow sea
bed. Place the plastic in position as
shown below.