Answer: Zero.
- A Positive
- B Negative
- C Zero
- D Maximum
Correct answer: C. Zero
Explanation: Gravity acts toward center; satellite moves tangentially. They are perpendicular, so work = F.d.cos(90) = 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.