Answer: 3.6 x 10 6 J.
- A 1000 J
- B 3.6 x 10<sup>6</sup> J
- C 3600 J
- D 1000 kJ
Correct answer: B. 3.6 x 10<sup>6</sup> J
Explanation: 1 kWh = 1000 W x 3600 s = 3.6 x 10<sup>6</sup> J = 3.6 MJ.
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.