I have just started the BFSU Vol 1 though my kids are 11 and 9. We are all learning a lot and we are just on Lesson C1! In going through this lesson, I had two questions:
1. How is magnetic energy categorized?
2. What makes the heart beat / cells divide? (Perhaps this is outside the realm of this lesson, regarding living things, but something I’ve always wondered – where/what is the “original battery” that keeps the heart pumping, etc?)
Magnets and magnetic fields can and do exist apart from any energy input/output (see Lesson A-5A). The pull or push experienced when playing with magnets is a force not energy. The distinction between force and energy is addressed in Lesson C-5A. This is to say that at this level, I would keep them separate and not attempt to get into “magnetic energy.”
Regarding your second question, energy for the heart’s pumping and all other body movements including cell division, comes from the potential energy in food molecules. That energy is released as the molecules are oxidized in cells (see Lesson B-9). Of course there are many more details that you might go into as you wish.
Thank you for your questions. Please ask further as you wish.