A ship uses sonar to find the depth of the sea.
A pulse of sound is sent down from the bottom of the ship. The pulse reflects from the sea bed and is detected back at the ship.
The frequency of the sound is 30 kHz30\ \text{kHz}30 kHz.
The speed of sound in sea water is 1500 m/s.
Use the equation: wave speed=frequency×wavelength\text{wave speed} = \text{frequency} \times \text{wavelength}wave speed=frequency×wavelength
Calculate the wavelength of the sound in sea water. Give your answer in m\text{m}m.
The pulse is detected back at the ship 0.80 s after it was sent.
Use the equation: distance=speed×time\text{distance} = \text{speed} \times \text{time}distance=speed×time
Calculate the depth of the sea.
Not all of the sound is reflected at the sea bed.
State two other things that can happen to the sound at the sea bed.
52 exam-style questions on OCR GCSE Physics 5.1 Wave behaviour, covering 5.1.1 Describing wave motion, 5.1.2 Wavelength and frequency, 5.1.3 Wave speed, frequency and wavelength, 5.1.4 Wave speed problems, 5.1.5 Transverse and longitudinal waves, 5.1.6 Sound waves crossing between media, 5.1.7 Reflection, transmission and absorption at interfaces, 5.1.8 Sound waves and vibrations in solids, 5.1.9 Frequency range and human hearing, 5.1.10 Modelling waves with water ripples and sound, and 5.1.11 Evidence that the wave travels, not the medium. Each one has a worked solution and a mark scheme showing where the marks go.