Sydneyâs coolest months are June to August when average temperatures drop between 8.8 - 17Â°C (47.8 - 62.6Â°F). Sydneyâs rainfall is generally highest in June, with an average of 132 mm (5.2â), while July is the coolest month when average daytime temperatures reach just 13Â°C (55Â°F). Spring (September â November)
The human ear responds to sounds with frequencies in the range from 20 Hz to 20,000 Hz. This is called the audible range of the human ear.
But the full range of wavelengths included in the definition of electromagnetic radiation extends from 0.1 nanometers, as in gamma rays, to centimeters and meters, as in radio waves. Light waves also come in many frequencies. The frequency is the number of waves that pass a point in space during any time interval, usually one second. We measure it in units of cycles (waves) per second, or hertz. The frequency of visible light is referred to as color, and ranges from 430 trillion hertz, seen as red, to 750 trillion hertz, seen as violet.