✓ Sources checked · 10 September 2026 · View verification
A pendulum exchanges gravitational potential energy and kinetic energy as it swings. For a small-angle simple pendulum, its period is approximately P = 2π√(L/g).
By Matan · Updated
Which pendulum?
The simple model uses a point bob on a massless inextensible string of length L. A rigid distributed body is a physical pendulum and needs its pivot-axis inertia. The simple period is approximately independent of amplitude only for small swings, not for every amplitude. [1]
Worked length comparison
For L = 0.50 m and g = 9.8 m/s², P = 1.42 s. Increasing length to 2.0 m gives P = 2.84 s. Quadrupling length doubles the period. Doubling bob mass leaves this ideal period unchanged.
Where the speed is greatest
At a turning point the bob’s speed is zero; at the bottom it is greatest. In the ideal model, energy is exchanged without loss. Real drag and pivot friction reduce amplitude. A clock mechanism must replenish those losses; the pendulum regulates timing rather than generating energy without an input. [1]
Claims about future technology
An oscillating pendulum stores a finite amount of mechanical energy. Attaching a generator extracts that energy and damps the motion unless another source replenishes it. Claims of superior storage efficiency require actual measurements and comparisons, not the existence of periodic motion.
Continue learning
How this article was checked
Sources checked; calculations checked where shown. The definitions, model assumptions and main explanatory claims were cross-checked against the sources below. Worked-example arithmetic and units were checked separately. These examples are illustrative calculations, not experimental measurements.
Source cross-check and editing assisted by AI. No independent human scientific review is recorded for this revision. The check applies to the version dated 10 September 2026; it is not a guarantee that every possible interpretation is correct.
Report an issue or request a fact-check · Editorial standards
Sources and further reading
- OpenStax: Simple and physical pendulums — Simple and physical pendulums.
Cite this article
Matan. “The science of pendulums.” Your Physicist. Originally published 2023-05-17; updated 2026-09-10. https://your-physicist.com/the-science-of-pendulums/
Revision history
: Qualified amplitude independence and clock energy; removed unsupported future-efficiency claims and added a checked period comparison. Added linked sources and a transparent verification record.
