Answer: Change in its kinetic energy.
- A Its potential energy
- B Its total energy
- C Change in its kinetic energy
- D Change in its momentum
Correct answer: C. Change in its kinetic energy
Explanation: Work-energy theorem: W<sub>net</sub> = Delta KE = (1/2)mv_f<sup>2</sup> - (1/2)mv_i<sup>2.</sup>
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.