A survey team uses an ultrasound transducer at the surface of a flooded quarry. The transducer sends a pulse vertically downwards.
The first echo is produced at the top of a layer of sediment. The second echo is produced at the boundary between the sediment and the solid rock below it.
| echo | time after pulse is sent / ms |
|---|---|
| first | 120 |
| second | 125 |
The speed of ultrasound in the water is 1480 m/s.
The speed of ultrasound in the sediment is 1800 m/s.
Calculate the distance from the transducer to the top of the sediment.
Calculate the thickness of the sediment layer.
The survey team changes to an ultrasound pulse with a higher frequency.
Give one reason why this could improve the measurement of a thin sediment layer.
112 exam-style questions on Edexcel GCSE Physics 4.3 Sound, ultrasound and infrasound, covering 4.3.1 Sound waves, vibrations and the human ear, 4.3.2 Ultrasound and infrasound, 4.3.3 Uses of ultrasound and infrasound, and 4.3.4 Sound waves passing between media. Each one has a worked solution and a mark scheme showing where the marks go.