EVERYDAY SCIENCE

Detailed explanation-1: -Infrasound or infrasonic, in its popular definition, is sound below a frequency of 20 Hz. It is a term used to determine the frequency of the sound vibration Infrasound has a range of 0.1 Hz to 20 Hz. Hence, the wave refers to an infrasonic wave that has a frequency of 5 Hz.

Detailed explanation-2: -If the woodpecker drums upon a tree 5 times in one second, then the frequency is 5 Hz; each drum must endure for one-fifth a second, so the period is 0.2 s.

Detailed explanation-3: -When a sound wave of frequency 300 Hz passes through medium, the maximum displacement of a particle of the medium is 0.1 cm.

Detailed explanation-4: -0.67 Hz (2 sig fig) 30 waves passing a point in 1 minute. The period (T) of a wave is the time taken for one complete wave to pass a point.