Final answer:
The energy exchange that occurs as a clock spring unwinds is a weak spring deforms a long way. When a clock is wound, potential energy is stored in the spring.
Step-by-step explanation:
The energy exchange that occurs as a clock spring unwinds is a weak spring deforms a long way. When a clock is wound, potential energy is stored in the spring. As the spring unwinds, the potential energy is gradually converted into kinetic energy, causing the clock to tick and the hands to move.