Motion changes to chemical energy. Stored energy changes to motion. Electricity changes to stored energy. Heat changes to electricity.
I gave my students this multiple choice question: A handheld sewing machine uses a battery to make a needle move. The needle goes up and down quickly. Which energy change is taking place?

Only one answer is correct among these 4 choices:
- Motion changes to chemical energy.
- Stored energy changes to motion.
- Electricity changes to stored energy.
- Heat changes to electricity.

Could you tell me which one is correct?

Stored energy changes to motion.