An inspection probe sends an ultrasound pulse into a concrete bridge support. An echo from a boundary around an internal void is detected 36 μs36\ \mu\text{s}36 μs after the pulse is sent. Ultrasound travels through the concrete at 4000 m/s.
Calculate the distance from the surface of the support to the boundary that produced the echo.
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.