Past exam of the physics course of the year 1 of the natural sciences course of the University of Cambridge / 2024 / Paper 1 / Section B / 8 / e / Solution

At the initial turning point the oscillation energy is $E=Mg{h}_0=0.04905\mathrm{J}$. In the high-quality factor regime, $Q=2\pi E/\Delta E$, so the required input per period isThis replaces the small dissipated energy each cycle, rather than supplying the entire stored energy again.