| Cue / Question | Notes |
|---|---|
| KE formula in SHM? | KE = ½mω^{2}( - ) — maximum at x = 0, zero at x = ±A |
| PE formula in SHM? | PE = ½mω^{2} — zero at x = 0, maximum at x = ±A |
| Where does KE = PE? | x = A/√2 ≈ 0.707A; each equals ½ × total energy |
| Series springs k_eff? | 1/k_eff = 1/k_{1} + 1/k_{2} → softer → longer T |
| Parallel springs k_eff? | k_eff = k_{1} + k_{2} → stiffer → shorter T |
| Pendulum in lift going up? | g_eff = g + a → T decreases (faster oscillation) |
| Pendulum in lift going down? | g_eff = g - a → T increases (slower oscillation) |
| Spring independent of? | Amplitude and gravity — works in space |
| Pendulum independent of? | Mass and amplitude (for θ < 15°) |
Summary: Energy in SHM oscillates between KE and PE keeping total constant. Spring-mass period depends on m and k only; pendulum depends on L and g only. Effective g changes in non-inertial frames.