Before generation
Use before or after a turntable, rotating stopper, simulation, or video investigation when learners need a visible prediction and comparison table. The planner supports a constant-speed, fixed-radius model. It does not infer radius from video, calculate uncertainty, verify attachment strength, select safe apparatus settings, or model changing speed, noncircular paths, drag, friction, or string mass.
Worked example
The example compares four fictional trials. Holding the 0.50 m radius while halving period from 2.00 s to 1.00 s makes modeled acceleration four times as large. A larger-radius trial shows the separate radius effect. Three claims fall within the disclosed two-percent comparison threshold, while the review trial remains visible with its calculated relative error.
Formula or methodology
Tangential speed is circumference divided by period: v = 2 pi r / T. Centripetal acceleration is v squared divided by r, equivalently 4 pi squared r divided by T squared. Required net inward force is mass times centripetal acceleration. Claim error is the absolute claimed-minus-modeled acceleration divided by modeled acceleration, expressed as a percentage.
How to interpret the result
A claim within two percent agrees numerically with this ideal model and the entered rounded data; it does not certify the apparatus or experimental result. Compare the model with measured uncertainty, repeat trials, inspect whether radius stayed fixed, and identify which forces combine to provide the radial net force. A large error should trigger unit, period-count, radius-reference, and transcription checks.
Common mistakes
Do not use diameter as radius, confuse period with frequency, time several turns without dividing by the turn count, treat centripetal force as an extra force, or point acceleration along the motion. Do not mix centimeters with meters or grams with kilograms unless the full unit system is converted consistently. Apply safety limits outside this model.