Measuring and the pendulum
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What this model shows
A simple pendulum: a small heavy bob on a light string, swinging through about 8° each side, with no air resistance. Its period is calculated as T = 2π√(l/g) with g = 9.8 m/s². The lengths are 0.10 m to 0.50 m, measured from the pivot to the centre of the bob.
When you time by hand, the stop-clock records your own presses: any spread in your readings comes from you, not from the model. A press counts if it comes up to about 0.15 s before or 0.30 s after the bob passes the marker (less on the shortest pendulums). The swing pauses while the page is hidden or scrolled away, and goes on by itself when you come back.
The simulated timer (allowed after the first length) presses the clock for you with a human-like delay of about 0.2 s at the start and at the stop. Its readings are marked * in your results. With reduced motion the bob is drawn still and the simulated timer times every length, including the first.
A real pendulum also slows down a little as it swings, and very large swings take a little longer. Real readings are taken in a lab; these are simulated apparatus.
Select equipment to read its description in the card.