MathCastle
TrigonometrySuperchallenge

Trigonometry · Superchallenge problem

A bicycle's odometer assumes the wheel's rolling radius is always exactly 3030 cm, and so reports a distance of 2π⋅302\pi\cdot30 cm for every wheel rotation. Over the course of a 1000010000-rotation ride the tire actually wears down evenly, so its TRUE rolling radius decreases from exactly 3030 cm at the first rotation to exactly 2929 cm at the ten-thousandth, shrinking by the same tiny amount on each successive rotation. Modelling each rotation as a circle at its own true radius, find by how many cm the odometer's reported distance OVERSTATES the bicycle's true distance travelled.

Practice more like this