Answer: 1.
- A 0
- B 0.5
- C 1
- D Greater than 1
Correct answer: C. 1
Explanation: e = (relative speed after) / (relative speed before). For elastic: e = 1. For inelastic: 0 < e < 1. For perfectly inelastic: e = 0.
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.