An industrial active sonar probe is placed against the flat face of a concrete support pillar on an offshore wind turbine to check for internal structural defects. A signal generator sends high-frequency sound pulses into the concrete, and a receiver detects any reflections from internal air or water voids.
An oscilloscope screen displaying the transmitted pulse and the reflected pulse from an internal void is shown below:
Which of the following is equivalent to 4.5 microseconds (μs)4.5\text{ microseconds } (\mu\text{s})4.5 microseconds (μs)?
- 4.5 × 10-3 s
- 4.5 × 10-6 s
- 4.5 × 10-9 s
- 4.5 × 10-12 s
Ultrasound waves travel at 4000 m/s through this concrete structure.
Determine the depth of the internal void below the front surface of the concrete pillar.
Give your answer to two significant figures.
Waves in air, fluids and solids Questions
Practise AQA GCSE Physics Waves in air, fluids and solids with exam-style questions for Foundation and Higher tier. 45 questions covering Transverse and longitudinal waves, Properties of waves, Reflection of waves (physics only), Sound waves (physics only) (HT only), and Waves for detection and exploration (physics only) (HT only), matched to the AQA GCSE Physics (8463) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.