Answer: mg + mv²/L.
- A mg + mv²/L
- B mg
- C mv²/L
- D mg - mv²/L
Correct answer: A. mg + mv²/L
Explanation: At the lowest point, T - mg = mv²/L (centripetal force equation). So T = mg + mv²/L.
In SHM, displacement and velocity are 90° out of phase (v is maximum when x=0, and zero when x is extreme), while acceleration is always exactly opposite in sign to displacement, consistent with a = −ω²x.
Concept context
Simple harmonic motion, spring-mass, pendulum, energy in SHM, and resonance.