Answer: 25 m.
- A 12.5 m
- B 25 m
- C 50 m
- D 10 m
Correct answer: B. 25 m
Explanation: d = v²/(2μg) = 100/(2·0.2·10) = 25 m.
As a pendulum swings, total mechanical energy (KE+PE) stays constant: at the highest points A and C, all energy is potential (zero speed); at the lowest point B, all of that energy has converted into kinetic energy (maximum speed).
Concept context
Work-energy theorem, potential energy, conservation of energy, collisions.