Can anyone identify this German 1980s (?) movie? Female students at a Catholic girls' school experience a conflict between expectations and their budding sexuality. The physics teacher was understanding and friendly.

I watched this movie around 1990 and would like to watch it again.

In a scene that I remember in particular, the physics teacher explains how friction between two bodies can cause a discharge of static electricity. It is quite obvious that the students are thinking about boys, not about physics. The young (male) physics teacher is not so silly that he doesn't understand the situation of his students, and he lets out a goofy smile in quiet acceptance.

I would be very grateful if anyone could help me find my old movie!