| English | Period |
|---|---|
| Bahasa Melayu | Tempoh |
| 中文 | 周期 |
Definition
The time taken to complete one full oscillation or one complete wave; measured in seconds (s).
In exam terms
Period is the time taken to complete one full oscillation or to produce one complete wave. Its symbol is T and its unit is the second (s).
Period is the reciprocal of frequency: T = 1 ÷ f, with f in Hz. For example, a wave of frequency 25 Hz has period T = 1 ÷ 25 Hz = 0.04 s.
You can also find the period by timing several oscillations and dividing: if a pendulum makes 20 swings in 30 s, T = 30 s ÷ 20 = 1.5 s. On a displacement-time graph the period is the horizontal length of one complete cycle.
Do not confuse it with wavelength
Period is a time (seconds) read from a displacement-time graph, while wavelength is a distance (metres) read from a displacement-distance graph. Both look like one complete cycle, so always check the horizontal axis before you answer.
In Paper 2 you may be asked to define period, to determine it from a graph, or to calculate it with T = 1 ÷ f. To reduce timing error in an experiment, time many oscillations and divide by the number of oscillations, then give T in seconds.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)