Answer: [ML 2 T -2 ].
- A [ML<sup>2</sup>T<sup>-2</sup>]
- B [MLT<sup>-2</sup>]
- C [ML<sup>2</sup>T<sup>-1</sup>]
- D [MLT<sup>-1</sup>]
Correct answer: A. [ML<sup>2</sup>T<sup>-2</sup>]
Explanation: Work = force × displacement = [MLT<sup>-2</sup>][L] = [ML<sup>2</sup>T<sup>-2</sup>], the same as energy.
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.