Everything Science Grade 10

CHAPTER 8. TRANSVERSE WAVES 8.7

• The wavelength (λ) is the distance between any two adjacent points on a wave that
  are in phase. It is measured in metres.


• The period (T) of a wave is the time it takes a wavelength to pass a fixed point. It is
  measured in seconds (s).


• The frequency (f) of a wave is how many waves pass a point in a second. It is
  measured in hertz (Hz) or s−^1.


• Frequency:f=^1 T


• Period:T=f^1


• Speed:v=f·λorv=λT.

Physical Quantities

Quantity Unit name Unit symbol

Amplitude (A) metre m

Wavelength (λ) metre m

Period (T) second s

Frequency (f) hertz Hz (s−^1 )

Wave speed (v) metre per second m·s−^1

Table 8.1: Units used intransverse waves

Chapter 8 End of chapter exercises

1. A wave travels along a string at a speed of 1 , 5 m·s−^1. If the frequency of

the source of the wave is 7,5 Hz, calculate:

a. the wavelength of the wave

b. the period of the wave

2. Water waves crash against a seawall around the harbour. Eight waves hit

the seawall in 5 s. The distance between successive troughs is 9 m. The

height of the waveform trough to crest is 1,5 m.

a. How many complete waves are indicated in the sketch?

Physics: Waves, Sound and Light 155