End of chapter exercises

A wave travels along a string at a speed of \(\text{1,5}\) \(\text{m·s$^{-1}$}\). If the frequency of the source of the wave is \(\text{7,5}\) \(\text{Hz}\), calculate:

1. the wavelength of the wave

2. the period of the wave

Water waves crash against a seawall around the harbour. Eight waves hit the seawall in \(\text{5}\) \(\text{s}\). The distance between successive troughs is \(\text{9}\) \(\text{m}\). The height of the waveform trough to crest is \(\text{1,5}\) \(\text{m}\).

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

2. Write down the letters that indicate any TWO points that are:

   1. in phase

   2. out of phase

   3. Represent ONE wavelength.

3. Calculate the amplitude of the wave.

4. Show that the period of the wave is \(\text{0,625}\) \(\text{s}\).

5. Calculate the frequency of the waves.

6. Calculate the velocity of the waves.