Answer: Remains constant.
- A Increases
- B Decreases
- C Remains constant
- D Becomes zero
Correct answer: C. Remains constant
Explanation: With no air resistance, total mechanical energy (KE + PE) is conserved during free fall.
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.