Two researchers, A and B, conduct an experiment to determine the speed of sound in air. They stand side by side at a distance of 510 m510\text{ m}510 m from a tall, flat vertical cliff.
Researcher A makes a sharp, loud sound by clapping two wooden boards together once. A short time later, both researchers hear the sound reflected from the cliff.
State the physics term used for a reflected sound wave.
As the sound wave travels to the cliff and reflects back, certain properties of the wave change, while others remain the same. State which property—frequency, speed, or amplitude—decreases as a result of reflection and travelling through the air.
Suggest a suitable manual device that researcher B can use to measure the time interval between hearing the initial clap and the reflected sound.
Using this device, researcher B measures a time interval of 3.0 s3.0\text{ s}3.0 s.
Calculate the speed of sound in air based on these measurements. Show your working.
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.