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Energy in SHM (KE ↔ PE)

Key Concepts — Energy in SHM (KE ↔ PE)

01

Energy in SHM oscillates between KE and PE but total stays constant.

02

KE: ½mv² = ½m·ω²·(A² − x²). Maximum (½mω²A²) at x = 0, zero at x = ±A.

03

PE: ½kx² = ½m·ω²·x². Maximum (½mω²A²) at x = ±A, zero at x = 0.

04

Total: E = ½kA² = ½mω²A² — depends on amplitude squared.

05

PE and KE oscillate at TWICE the SHM frequency (sin² and cos² have period T/2).

06

Time-average of KE over a period = time-average of PE = ½ × Total energy.

07

Doubling amplitude QUADRUPLES total energy.

08

Energy conservation: ½kx² + ½mv² = ½kA² always.