Answer: 10 kW.
- A 1 kW
- B 5 kW
- C 10 kW
- D 100 kW
Correct answer: C. 10 kW
Explanation: P = mgh/t = 100·10·10 = 10000 W = 10 kW.
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.