Focus Physics

1.1.3 — Determine an average value for a small distance and for a short interval of time by measuring multiples (including the period of oscillation of a pendulum)

1.1.3 — Determine an average value for a small distance and for a short interval of time by measuring multiples (including the period of oscillation of a pendulum)

When distances or times are very small, measuring once is unreliable. Instead, measure many repetitions.

Examples:

1. Measuring a very small distance

Suppose you want the thickness of one sheet of paper:

  • Measure the thickness of 100 sheets.
  • Divide by 100.

This reduces error by averaging out tiny uncertainties.

2. Measuring a short time: the period of a pendulum

A pendulum swings too quickly to time one oscillation accurately.

Steps:

  • Time 20 oscillations using a stopwatch.
  • Divide total time by 20 → period, T.

Real-world example:

Scientists measuring microscopic distances or tiny time intervals always measure multiples — the same principle used by astronomers timing pulsars or engineers measuring vibration frequencies.

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