  We describe an extracurricular learning path on waves focused on energy
transfer. The advantages of introducing mechanical waves by using the Shive
wave machine and laboratory activities are presented. Laboratories are realized
by inquiry, i.e. students explore waves behavior in qualitative way, guess what
can happen and suddenly test their hypothesis. Recently, we presented some
disciplinary knots that arise usually in empirical investigation, according to
the Model of Educational Reconstruction and discussed methodological choices
made in designing the learning path and preliminary result about its
realization with few, interested and talented pupils. We report the second year
of this learning path performed with the same students that are introduced to
more complex topics such as analogy in wave phenomena and resonance.
Laboratories are described with particular attention for the energy
transformation. We designed the activities in order to propose a complementary
experience compared to what was done in class. Despite resonance is a relevant
phenomenon which runs through almost every branch of physics, many students
have never studied it. Yet, resonance is one of the most striking and
unexpected phenomenon in all physics and it easy to observe but difficult to
understand. Students performed activities in laboratory on several resonant
systems. Our purpose was to outline how it is possible to tune a system or a
device in order to obtain resonance and an efficient energy transfer from
different physical systems, such as a mechanical one and an electrical one.
This year, the final task was to analyze different natural phenomena in order
of choosing one suitable for energy transfer. We present our considerations on
the students' learning process and on the possibility of extend a similar path
in a classroom.
