Sound of different frequency bands is used in many day-to-day applications. Study the statements below and answer the questions.
(i) List any two uses of ultrasound in medicine or industry.
(ii) For one use stated in part (i), explain briefly how the high frequency of ultrasound helps in that application.
(iii) Explain why infrasound produced by elephants can travel larger distances through air than an audible sound of the same power.