Energy conversion during free fall phase Steps:

• Total drop to lowest point is 30 m, so halfway is 15 m below platform.
• Unstretched rope length is 20 m, so at 15 m the rope remains slack.
• Initial gravitational PE converts entirely to kinetic energy via mgΔh = (1/2)mv².
• No stretching occurs, so no elastic PE is stored.

Why C is correct:

• Before the rope tautens, conservation of energy dictates gravitational PE loss equals kinetic energy gain only.

Why the others are wrong:

• A: Elastic PE requires rope stretching, which starts at 20 m.
• B: Elastic PE is absent; kinetic energy dominates from free fall.
• D: Elastic PE is absent; kinetic energy dominates from free fall.

Final answer: C