A wildlife conservation group uses an acoustic beacon that emits sound at a frequency of 15 Hz to guide herd movements.
Explain why this signal can be detected by elephants but cannot be heard by the human conservationists operating the device.
35 exam-style questions on Edexcel GCSE Physics 4.3 Sound, ultrasound and infrasound (physics only). Each one has a worked solution and a mark scheme showing where the marks go.