Answer: 0.2 m.
- A 0.4 m
- B 0.1 m
- C 2.0 m
- D 0.2 m
Correct answer: D. 0.2 m
Explanation: Momentum: v = (0.01×200)/1.0 = 2 m/s. Then energy conservation: h = v<sup>2</sup>/2g = 4/20 = 0.2 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.