Calculate period from frequency.

To calculate period from frequency, students use T = 1/f and give the answer in seconds. If the frequency is 5 Hz, the period is 0.2 s because each complete wave takes one fifth of a second. This objective should be explained as a time calculation, not a speed calculation. It reinforces that frequency and period are reciprocals: increasing frequency means each wave cycle takes less time. Within the subtopic Properties of waves in Waves in air, fluids and solids, the explanation is anchored to frequency, period and uses those terms in the approved AQA GCSE Physics Waves context.