An athletics coach is trying to measure the speed of sound in air using an echo method.
She has a starting pistol (which produces both a bright flash and a loud report), a digital stopwatch, and a long tape measure.
Suggest one suitable large object that she could use as a sound reflector.
She stands a measured distance of 255textm255\\text{ m}255textm from her chosen reflector and fires the pistol safely.
Identify what she should see or hear to start the stopwatch.
Identify what she should hear to stop the stopwatch.
The stopwatch registers a time of 1.50texts1.50\\text{ s}1.50texts.
Using this time and the distance from (b), calculate the speed of sound in air.
Suggest one reason why the calculated speed of sound might not be highly accurate, assuming that the stopwatch and tape measure function correctly.
295 exam-style questions on CIE IGCSE Physics Sound, covering Sound. Each one has a worked solution and a mark scheme showing where the marks go.