Knox Academy S3 and S4 Physics Waves Throughout the Course, appropriate attention should be given to units, prefixes and scientific notation. Prefix Symbol Notation Operation tera T 1012 x 1,000,000,000,000 giga G 109 x 1,000,000,000 mega M 106 x 1,000,000 kilo k 103 x 1,000 centi c 10-2 /100 milli m 10-3 /1,000 micro µ 10-6 /1,000,000 nano n 10-9 /1,000,000,000 pico p 10-12 /1,000,000,000,000 In this section the prefixes you will use most often are milli (m), micro (µ), kilo (k), mega (M) and giga (G). It is essential that you use these correctly in calculations. In Physics, the standard unit for time is the second (s) and therefore if time is given in milliseconds (ms) or microseconds (µs) it must be converted to seconds. Example 1 a) A wave takes 40 ms to pass a point. How many seconds is this? 40 ms = 40 milliseconds = 40 x 10-3 s = 40/1 000 = 0.040 seconds. µs, b) A faster wave travels past in a time of 852 how many seconds is this? µs 852 = 852 microseconds = 852 x 10-6 s = 852/1 000 000 = 0.000852 seconds. In Physics, the standard unit for distance is the metre (m) and therefore if distance is given in kilometres (km) it must be converted to metres. Example 2 A wave travels 26.1 km in 0.5 ms. How far in metres has it travelled? 26.1 km = 26.1 kilometres = 26.1 x 103 m = 26.1 x 1 000 = 26 100 metres. This unit involves calculations which use the term frequency, frequency has units of hertz (Hz) although often we meet the terms Megahertz and Gigahertz.
Knox Academy S3 and S4 Physics Waves Throughout the Course, appropriate attention should be given to units, prefixes and scientific notation. Prefix Symbol Notation Operation tera T 1012 x 1,000,000,000,000 giga G 109 x 1,000,000,000 mega M 106 x 1,000,000 kilo k 103 x 1,000 centi c 10-2 /100 milli m 10-3 /1,000 micro µ 10-6 /1,000,000 nano n 10-9 /1,000,000,000 pico p 10-12 /1,000,000,000,000 In this section the prefixes you will use most often are milli (m), micro (µ), kilo (k), mega (M) and giga (G). It is essential that you use these correctly in calculations. In Physics, the standard unit for time is the second (s) and therefore if time is given in milliseconds (ms) or microseconds (µs) it must be converted to seconds. Example 1 a) A wave takes 40 ms to pass a point. How many seconds is this? 40 ms = 40 milliseconds = 40 x 10-3 s = 40/1 000 = 0.040 seconds. b) A faster wave travels past in a time of 852 µs, how many seconds is this? 852 µs = 852 microseconds = 852 x 10-6 s = 852/1 000 000 = 0.000852 seconds. In Physics, the standard unit for distance is the metre (m) and therefore if distance is given in kilometres (km) it must be converted to metres. Example 2 A wave travels 26.1 km in 0.5 ms. How far in metres has it travelled? 26.1 km = 26.1 kilometres = 26.1 x 103 m = 26.1 x 1 000 = 26 100 metres. This unit involves calculations which use the term frequency, frequency has units of hertz (Hz) although often we meet the terms Megahertz and Gigahertz.
waves_summary_notes.docx